DEF 14A of ADTRAN Holdings, Inc., Mar 27, 2026

DEF 14A of ADTRAN Holdings, Inc.

Filed Mar 27, 2026 · FY20250001193125-26-127315

Open on EDGAR

  1. Election of Directors

    Election of Directors

  2. Our Board of Directors

    Our Board of Directors Our Bylaws provide that the exact number of directors will be fixed from time to time by our Board pursuant to a resolution adopted by a majority of the whole Board. Our Board of Directors currently consists of seven members. Balan Nair, a current director, was not nominated by our Board of Directors for re-election. The decision not to nominate Mr. Nair for re-election was not due to a disagreement with our management or Board, and we extend our gratitude and appreciation to Mr. Nair for his contributions to the Company. The Board has nominated Thomas R. Stanton, H. Fenwick Huss, Gregory J. McCray, Jacqueline H. Rice, Nikos Theodosopoulos and Kathryn A. Walker for election as directors at the 2026 Annual Meeting. Each of these individuals currently serves as a director. Following the Annual Meeting, if each nominee is elected, our Board will consist of six members. If elected as a director at the Annual Meeting, each of the nominees would serve a one-year term expiring at the 2027 Annual Meeting of Stockholders and until his or her successor has been duly elected and qualified. There are no family relationships among the directors, director nominees or the executive officers. Pursuant to the Company’s Director Resignation Policy, each of the director nominees is deemed to have agreed to promptly tender to the Chairman of the Board of Directors an irrevocable contingent resignation in the event that such director fails to receive a sufficient number of votes for re-election (a “majority against vote”). If any director nominee receives a majority against vote at the Annual Meeting, the Nominating and Corporate Governance Committee of the Board of Directors will recommend to the Board, and the Board will determine, whether to accept or reject the resignation tendered by such individual. Following the Board’s decision, the Company will file a Current Report on Form 8-K with the SEC in order to disclose the decision and, if applicable, the Board’s reasoning for rejecting the tendered resignation. Our Board of Directors seeks to ensure that the Board is composed of members whose experience, qualifications, attributes and skills, when taken together, will allow the Board to satisfy its oversight responsibilities effectively in light of the Company’s business and the laws and stock exchange rules that govern its affairs. We have no minimum qualifications for director candidates. In general, however, our Board will review and evaluate both incumbent and potential new directors in an effort to achieve diversity of skills and experience among our directors so that our Board has an effective mix of technical, financial, operating and management experience. Our Board has adopted corporate governance principles to guide the Company and the Board on various governance matters, and these principles task the Nominating and Corporate Governance Committee of the Board with establishing criteria for the selection of potential directors, taking into account the following desired attributes (solely related to the six director nominees): leadership; independence; interpersonal skills; financial acumen; business experiences; industry knowledge; and a diversity of viewpoints. We believe that our Board should be comprised predominantly of independent directors from diverse backgrounds external to the Company, but should nevertheless include the insight and judgment of our senior management. Our Board has no specific requirements regarding diversity. In assessing the experience, qualifications, attributes and skills that led our Nominating and Corporate Governance Committee and Board to conclude that each director has the appropriate qualifications to serve as a director of the Company, the Board focused on the information discussed in each of the director nominees’ individual biographies set forth on pages 11 to 17 of this Proxy Statement. In evaluating the suitability of the director nominees for re-election, our Nominating and Corporate Governance Committee also considered the director’s past performance, including attendance at meetings and participation in and contributions to the activities of the Board and its committees, as applicable.

  3. Our Board of Directors

    | | 10 | 2026 Proxy Statement |

  4. Information Regarding the Nominees for Director

    Information Regarding the Nominees for Director Set forth below is certain information as of the date of this Proxy Statement regarding the six nominees for director, including their ages, principal occupations or employment for at least the past five years, the length of their tenure as directors, and the names of other public companies in which such persons hold or have held directorships during the past five years. Additionally, information about the specific experience, qualifications, attributes or skills that led to our Board’s conclusion at the time of filing of this Proxy Statement that each person listed below should serve as a director is set forth below. The stock ownership with respect to each director nominee and other director is set forth in the Security Ownership of Certain Beneficial Owners and Management table on page 8.

  5. Information Regarding the Nominees for Director

    | Thomas R. Stanton | | | Age: 61 Director Since: 2005 Board Committees: None | Background Information Thomas Stanton was named our Chief Executive Officer in September 2005 and named Chairman of the Board in 2007. He has also served as Chief Executive Officer and Chairman of the Board of ADTRAN International, Inc., a subsidiary of the Company formerly known as ADTRAN Asia-Pacific, Inc., since September 2005. Furthermore, he is the Chief Executive Officer of Adtran Networks SE, the Company's majority-owned subsidiary and formerly ADVA Optical Networking SE (“Adtran Networks”), and a member of its management board. Mr. Stanton joined Adtran in 1995 as Vice President of Marketing for the Carrier Networks (“CN”) Division. Since that time, he has held a number of senior management positions within the Company, including Senior Vice President and General Manager of the CN Division. Prior to joining Adtran, he served as Vice President of Marketing and Engineering at Transcrypt International and held several senior management positions with E. F. Johnson Company. Mr. Stanton has served on the board of directors of a number of technology companies and is a past chairman of the board for both the Federal Reserve Bank of Atlanta’s Birmingham Branch and the Telecommunications Industry Association. He also served on the board of Cadence Bank (NYSE: CADE), formerly BancorpSouth Bank, from October 2015 through February 2026, where he served on the Compensation Committee and as the Chair of the Risk Committee. In addition, Mr. Stanton previously served as a director of the Huntsville Chamber of Commerce, the Telecommunications Industry Association, and the Economic Development Partnership of Alabama. Mr. Stanton holds a Bachelor of Science degree in Computer Engineering from Auburn University. | | Qualifications Mr. Stanton has been selected as a nominee for director because he is our Chief Executive Officer and has extensive knowledge of all facets of our Company and extensive experience in all aspects of our industry. | |

  6. Information Regarding the Nominees for Director

    | | 11 | 2026 Proxy Statement |

  7. Information Regarding the Nominees for Director

    | H. Fenwick Huss | | | Age: 76 Director Since: 2002 Board Committees: • Audit (Chair) • Compensation • Sustainability • Nominating and Corporate Governance | Background Information Fenwick Huss retired from Baruch College, a senior college of The City University of New York, in December 2022, where he served as the Willem Kooyker Dean of the Zicklin School of Business from July 2014. He also served as a tenured Professor in Baruch’s Stan Ross Department of Accountancy. He previously served as Dean of the J. Mack Robinson College of Business at Georgia State University from 2004 to 2014. Prior to his appointment as Dean, Dr. Huss was Associate Dean from 1998 to 2004 and Director of the School of Accountancy at Georgia State from 1996 to 1998, and on the faculty since 1989. He also served on the faculty of the University of Maryland as an assistant professor from 1983 to 1989 and is a visiting professor at the Université Paris 1 Pantheon-Sorbonne. | | Qualifications Dr. Huss has been selected as a nominee for director because he brings the point of view of academia and, in particular, the information and new concepts that develop in the business school environment. Dr. Huss also has extensive experience and knowledge of financial accounting and corporate finance and management experience in the academic environment. | |

  8. Information Regarding the Nominees for Director

    | | 12 | 2026 Proxy Statement |

  9. Information Regarding the Nominees for Director

    | Gregory McCray | | | Age: 63 Director Since: 2017 Board Committees: • Audit • Compensation • Nominating and Corporate Governance | Background Information Gregory McCray is an experienced executive with more than 30 years of business, marketing, sales, engineering, operations, mergers and acquisitions, management and international experience in the communications technology industry. Since August 2024, Mr. McCray has served as the CEO of PBE Axell, a global company that provides communications systems, monitoring/tracking products, and proximity avoidance systems for industrial, commercial, and public safety markets. Prior to that, Mr. McCray held numerous management and executive roles, including: Chairman and CEO of FDH Infrastructure Services, an engineering, technology, and science company that develops products and software to monitor and inspect infrastructure assets (May 2018 to May 2024); CEO of Google Fiber, a provider of fiber broadband internet service (2017); CEO of Aero Communications Inc., which provides installation, services and support to the communications industry (2013 to 2016); CEO of Antenova, a developer of antennas and radio frequency modules for mobile devices (2003 to 2012); Chairman and CEO of PipingHot Networks, which brought broadband fixed wireless access equipment to market (2001 to 2002); and Senior Vice President of customer operations at Lucent Technologies, where he managed the Customer Technical Operations Group for Europe, the Middle East and Africa (1996 to 2000). Mr. McCray has also served on the board of directors of Belden Inc (NYSE: BDC), where he serves on the Finance Committee and the Nominating and Corporate Governance Committee, since February 2022; DigitalBridge Group, Inc. (NYSE: DBRG), where he serves as a member of the Nominating and Corporate Governance Committee and Chairman of the Compensation Committee, since January 2021; and FreeWave Technologies (a private Industrial IoT company) since 2019. Previously, Mr. McCray served as a director of CenturyLink, Inc. (NYSE: CTL), the third largest network operator in America, from January 2005 to February 2017, where he served as chairman of the Cyber Security & Risk Committee from 2015 to 2017. Mr. McCray holds a Bachelor of Science degree in Computer Engineering from Iowa State University and a Master of Science degree in Industrial & Systems Engineering from Purdue University. He has also completed executive business programs at Harvard, INSEAD, and the University of Illinois. He was inducted into the Iowa State University Engineering Hall of Fame in 2022. | | Qualifications Mr. McCray has been selected as a nominee for director because of his extensive experience as an executive and senior manager in the telecommunications and technology industries during the course of his career, as well as his experience as a director of publicly held companies. | |

  10. Information Regarding the Nominees for Director

    | | 13 | 2026 Proxy Statement |

  11. Information Regarding the Nominees for Director

    | Jacqueline H. (Jackie) Rice | | | Age: 54 Director Since: 2016 Board Committees: • Audit • Nominating and Corporate Governance (Chair) | Background Information Jackie Rice has served as Chief Legal Officer and Corporate Secretary of MillerKnoll, Inc. (NASDAQ: MLKN), a design and manufacturing company that researches, designs and manufactures interior furnishings for use in various environments, including residential, office, healthcare and educational settings, since May 2025. Previously, she served as General Counsel and Corporate Secretary of MillerKnoll, Inc. from February 2019 to May 2025. Prior to joining MillerKnoll, Inc., Ms. Rice served as Principal of RH Associates, a global consulting firm providing legal, risk and compliance advisory services for clients across all industries and geographies, from January 2018 to January 2019. From 2014 to 2017, Ms. Rice served as Target Corporation’s (NYSE: TGT) Executive Vice President and Chief Risk and Compliance Officer with responsibility for enterprise and vendor risk, corporate security and corporate compliance and ethics. Prior to joining Target, she served as Chief Compliance Officer and legal counsel of General Motors (NYSE: GM) from 2013 to 2014 and Executive Director, Global Ethics and Compliance of General Motors from 2010 to 2013. Ms. Rice served on the board of directors of the Michigan West Coast Chamber of Commerce for a four-year term from 2021 until 2024. Ms. Rice graduated from the University of Detroit Mercy School of Law, where she was editor-in-chief of the Law Review, and she obtained her undergraduate degree from James Madison College at Michigan State University. | | Qualifications Ms. Rice has been selected as a nominee for director because of her legal background and her experience with governance, compliance, ethics and risk management for large, publicly held corporations. | |

  12. Information Regarding the Nominees for Director

    | | 14 | 2026 Proxy Statement |

  13. Information Regarding the Nominees for Director

    | Nikos Theodosopoulos | | | Age: 63 Director Since: 2022 Board Committees: • Audit • Compensation (Chair) • Sustainability | Background Information Nikos Theodosopoulos served as chairman of the supervisory board of Adtran Networks from January 2015 until August 2022. He has served on the board of directors of Hercules Capital, Inc., a specialty finance company in the technology, life sciences and sustainable and renewable technology industries, since 2023. Mr. Theodosopoulos also previously served on the boards of Arista Networks (NYSE: ANET), a computer networking company, from March 2014 to June 2023 and Harmonic Inc. (NASDAQ: HLIT), a global provider of broadband access solutions and video delivery software, products, system solutions and services, from March 2015 to August 2022. Since August 2012, Mr. Theodosopoulos has served as an independent director, advisor and consultant in the technology and financial services industries through his advisory firm, NT Advisors LLC. From 1994 through 2012, he was an equity research analyst, primarily at UBS Group AG, an investment bank and financial services company, covering the technology sector, where he eventually served as Managing Director, Global Technology Strategist and Technology Sector Head of U.S. Equity Research. Prior to his career in investment banking, he spent 10 years at AT&T Network Systems and Bell Laboratories. He holds a Master of Business Administration from New York University, a Master of Science from Stanford University, and a Bachelor of Science from Columbia University. | | Qualifications Mr. Theodosopoulos has been a member of our Board since the closing of the Business Combination (as defined below) in July 2022. The skills that Mr. Theodosopoulos brings to the Board are instrumental to our achievement of synergies and global strategy going forward. Additionally, Mr. Theodosopoulos has been selected as a nominee for director because of his experience in the technology industry and his vast public board experience, including Chairman, Audit Committee Chair, and Compensation Committee Chair roles. | |

  14. Information Regarding the Nominees for Director

    | | 15 | 2026 Proxy Statement |

  15. Information Regarding the Nominees for Director

    | Kathryn A. Walker | | | Age: 66 Director Since: 2014 Board Committees: • Nominating and Corporate Governance • Sustainability (Chair) | Background Information Kathryn Walker has more than 30 years of experience in the communications industry. Since 2009, she has served as a managing director for OpenAir Equity Partners, a venture capital firm focusing on the wireless, communications and mobile internet sectors. Ms. Walker also served as the Chief Technology Officer of Main Street Data, an agriculture data science company founded by OpenAir Equity Partners, from 2020 to 2024. Prior to joining OpenAir Equity Partners, Ms. Walker worked in a variety of roles at various subsidiaries of Sprint Corporation from 1985 to 2009, culminating in the position of Chief Information and Chief Network Officer at Sprint Nextel Corporation. She currently serves on the Board of Governors and Council of Trustees of South Dakota State University Foundation, on the Board of Trustees of Missouri S&T, and as the Chair of the Kummer Missouri S&T Foundation. Ms. Walker is a National Association of Corporate Directors (“NACD”) Board Leadership member. Ms. Walker also was elected to the NACD Directorship 100 in 2021 in recognition of her corporate governance expertise. | | Qualifications Ms. Walker has been selected as a nominee for director because she has extensive experience with the technologies that influence our industry and our markets. She also possesses governance expertise and management experience, particularly managing technical personnel. | |

  16. Information Regarding the Nominees for Director

    | | 16 | 2026 Proxy Statement |

  17. Information Regarding Directors Not Standing for Re-Election

    Information Regarding Directors Not Standing for Re-Election Set forth below is certain information as of the date of this Proxy Statement regarding Mr. Nair, who will not be standing for re-election at the Annual Meeting.

  18. Information Regarding Directors Not Standing for Re-Election

    | Balan Nair | | | Age: 59 Director Since: 2007 | Background Information Balan Nair has served as President and Chief Executive Officer of Liberty Latin America Ltd. (NASDAQ: LILA) since 2018. Liberty Latin America is an integrated telecommunications company, focused on the Caribbean Islands and Latin America. Mr. Nair is an experienced and proven business executive with more than 20 years in the telecommunications industry. He has been a part of the Liberty family of companies since 2007, when he joined Liberty Global plc (NASDAQ: LBTYA) as its Senior Vice President and Chief Technology Officer. He most recently served as Executive Vice President and Chief Technology and Innovation Officer from 2007 to 2017. In this role, he was responsible for overseeing Liberty Global’s worldwide network, as well as Technology and Innovation operations, including Product Development, IT, Network Operations, Mobile Operations and Global Supply Chain functions. He was also responsible for Corporate Strategy and Venture Investments. Mr. Nair was an executive officer of Liberty Global and sat on Liberty Global’s Executive Leadership Team and the Investment Committee. Before joining Liberty Global, Mr. Nair served as Chief Technology Officer and Executive Vice President of AOL LLC, a global web services company. Prior to his role at AOL LLC, he spent more than 12 years at Qwest Communications International Inc., most recently as Chief Information Officer and Chief Technology Officer. Mr. Nair has a long history of working in the telephone, web world, and cable and media industries. He has served on the board of directors of Charter Communications, Inc. (NASDAQ: CHTR), a leading cable operator in the United States, since 2013, and on the board of Liberty Latin America since December 2017. He graduated from Iowa State University with a Bachelor of Science degree in Electrical Engineering and a Master of Business Administration degree. Mr. Nair holds a patent in systems development and is a Licensed Professional Engineer in Colorado. |

  19. Process for Stockholders to Recommend Director Nominees

    Process for Stockholders to Recommend Director Nominees As provided in its charter, the Nominating and Corporate Governance Committee will consider potential director candidates submitted by stockholders. To recommend a nominee, a stockholder should write to the Nominating and Corporate Governance Committee at ADTRAN Holdings, Inc., Attn: Corporate Secretary, 901 Explorer Boulevard, Huntsville, Alabama 35806 (for overnight delivery) or at P.O. Box 140000, Huntsville, Alabama 35814-4000 (for mail delivery). Any recommendation must include: the name and address of the nominee;

  20. Process for Stockholders to Recommend Director Nominees

    | | 18 | 2026 Proxy Statement |

  21. Process for Stockholders to Recommend Director Nominees

    all information relating to the nominee that is required to be disclosed in solicitations of proxies for election of directors pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended (the “Exchange Act”); a brief biographical description, including his or her occupation for at least the last ten years, and a statement of the qualifications of the nominee, considering the criteria set forth above; and • the nominee’s signed consent to be named in any proxy statement if nominated and to serve as a director if elected. The Corporate Secretary will promptly forward these materials to the Chair of the Nominating and Corporate Governance Committee and the Chairman of the Board. The Nominating and Corporate Governance Committee may contact a recommended candidate to request additional information about the candidate’s independence, qualifications and other information that would assist the Committee in evaluating the candidate. The Charter of the Nominating and Corporate Governance Committee and the Company’s Corporate Governance Principles set forth factors that the Board and the Nominating and Corporate Governance Committee may consider in evaluating a director nominee, regardless of the recommending party. In addition to submitting nominations in advance to the Nominating and Corporate Governance Committee for consideration, a stockholder also may nominate persons for election to the Board of Directors in person at a stockholders meeting. Section 3.4 of the Company’s Bylaws provides for procedures pursuant to which stockholders may nominate a candidate for election as a director of the Company. Furthermore, stockholders who intend to solicit proxies in support of director nominees other than the Company’s nominees must provide notice to the Company that complies with the informational and timing requirements of Rule 14a-19 under the Exchange Act to comply with the SEC’s universal proxy rules, in addition to satisfying the requirements under our Bylaws. The chairperson of the meeting shall have the power to determine and declare to the meeting whether or not a nomination was made in accordance with the procedures set forth in our Bylaws and, if the chairperson determines that a nomination is not in accordance with the procedures set forth in the Bylaws, to declare that the defective nomination will be disregarded. A copy of our Bylaws is available in the “Governance” section of our website at https://investors.adtran.com. Printed copies of the Bylaws may also be obtained at no charge by writing to the Corporate Secretary at ADTRAN Holdings, Inc., Attn: Corporate Secretary, 901 Explorer Boulevard, Huntsville, Alabama 35806.

  22. Process for Stockholders to Recommend Director Nominees

    | | 19 | 2026 Proxy Statement |

  23. Overview of Executive Compensation Program

    | | Compensation Element | Type | Description | Linkage to Stockholder Value | Specifications | | Fixed | Base Salary | Cash | • Short-term fixed compensation • Reviewed annually and adjusted as appropriate | • Required to attract and retain talented personnel • Predicated on responsibility, skills, and experience | • The Compensation Committee approved base salary increases of 3% for Messrs. Stanton and Wilson, as well as a greater than 10% increase in base salary for Dr. Glingener upon the renewal of his annual contract. • Mr. Santo's initial base salary was approved in connection with his appointment in March 2025. | | Performance-Based (Cash and Equity) | Short-Term Cash Incentives | Cash | • Short-term variable compensation • Payout based on performance against short-term financial and strategic objectives | • Incentive targets tied to key Company performance measures • Drives management to achieve corporate and individual goals | • 2025 cash awards were based on annual corporate goals. • Additionally, Mr. Wilson was eligible to earn a sales incentive payment. | | | Market-Based Performance Stock Units | Equity | • Long-term three-year cliff vesting award • Payout based on relative performance compared to peer group | • Performance based on TSR ranking compared to peers • Drives management to out-perform our market segment | 2025 awards were eligible to be earned based on TSR performance compared to industry index. | | | Performance-Based Performance Stock Units | Equity | • Long-term equity award • Payout based on achievement of the Company’s multi-year strategic plan objectives | • Incentive targets tied to profitability objectives in the 3-year strategic plan • Drives management to achieve the longer-term plan | The Company granted a Long-Term Financial Plan Award to Mr. Stanton in 2025. This award is tied to the same 3-year strategic plan objectives as the 2023 Long-Term Financial Plan (based on performance in the remaining one year of the performance period). Participants remain eligible to earn the previously granted 2023 Long-Term Financial Plan awards, which are based on the Company’s performance measured against the Company’s 3-year strategic plan for Adjusted EBIT growth. | | Retention Equity | Time-Based Restricted Stock Units | Equity | Annual award of time-based equity | • Value realized directly aligned with share price performance • Drives ownership mentality and encourages retention | 2025 time-based awards vest over a 4-year period, subject to continued service to the Company. | | | Stock Options | Equity | Equity award granted in special circumstances | Incentivizes management to achieve share price growth | The Company did not grant any stock options to its NEOs in 2025. Mr. Wilson’s 2023 stock options, which were granted in connection with his temporary salary reduction, finished vesting in 2025. |

  24. Role of the Compensation Committee and Management

    Role of the Compensation Committee and Management Under our Compensation Committee’s Charter, the Compensation Committee has the power and duty to discharge our Board’s responsibilities related to the compensation of our executive officers, within guidelines established by the Board. The Compensation Committee reviews and approves compensation, including base salary, annual incentive awards and equity awards, for the CEO and our other executive officers. The Compensation Committee also makes recommendations to the Board regarding our incentive compensation plans, equity plans and the outside director compensation program. The Committee establishes annual performance goals and objectives for the CEO and other executive officers based on annual performance evaluations. Our CEO also provides the Committee, and in particular, the Committee Chair, with recommendations regarding compensation for our executive officers other than himself. The Committee considers the recommendations from the CEO when approving pay changes for executives other than the CEO. The Committee has delegated to the CEO the authority to approve the base salaries and incentive compensation of non-executive employees, as well as equity grants to such individuals, subject to pre-approved limits and terms and conditions. At the beginning of each calendar year, our Compensation Committee establishes the structure of the Company’s incentive compensation programs for the current year, including setting the performance goals for the Variable Incentive Cash Compensation (the “VICC”) program and the standards for measuring achievement of those goals; approves any increases in executive salaries or other compensation; approves the executives’ annual and long-term equity grants; and recommends plan changes, if any, for submission to our stockholders at the annual meeting. The Committee approves any equity awards and/or compensation for newly hired or promoted executives as necessary throughout the year. In fulfilling its fiduciary duties pertaining to the Company’s employee retirement benefit plans, our Compensation Committee considers the information and advice it receives from a committee of Company personnel it established, chaired by the Chief Financial Officer, which reviews and monitors the performance of retirement plan investments and assets, the performance and fees of the Company’s retirement plan custodians and administrators, and the recommendations of third-party registered fiduciary advisors of our benefits plans, a process which includes quarterly meetings with these third parties.

  25. Role of the Compensation Consultant

    Role of the Compensation Consultant Our Compensation Committee has the authority to retain and terminate any outside advisors, such as compensation consultants. Starting in 2022 and continuing into 2025, the Committee engaged Pay Governance LLC, an independent compensation consultant ("Pay Governance"), at various times to provide information and analysis of our executive compensation in the context of the telecom industry and our peer companies in the industry and to present this information with possible modifications to our compensation of executives and directors for the Committee’s consideration. The Committee has worked with Pay Governance to develop a peer group of companies that is of similar size in market capitalization and revenues and representative of the marketplace within which the Company competes in terms of products, services and executive and managerial talent. The Company used the peer group approved in 2024, which is listed below, in connection with determining the 2025 compensation arrangements of our NEOs:

  26. Role of the Compensation Consultant

    | | 38 | 2026 Proxy Statement |

  27. Role of the Compensation Consultant

    | • Calix, Inc. | • Lumentum Holdings Inc. | | • Casa Systems, Inc. | • MACOM Technology Solutions Holdings, Inc. | | • Ciena Corporation | • Methode Electronics, Inc. | | • Comtech Telecommunications Corp. | • NETGEAR, Inc. | | • Extreme Networks, Inc. | • NetScout Systems, Inc. | | • Fabrinet | • OSI Systems, Inc. | | • Harmonic Inc. | • Ribbon Communications Inc. | | • Infinera Corporation | • Viavi Solutions Inc. |

  28. Role of the Compensation Consultant

    The Compensation Committee believes comparison to these companies is appropriate, given the limited number of comparable companies and direct competition with these peers for executive talent. The Compensation Committee also references various peer, industry and market compensation data when evaluating the appropriateness of the Company’s compensation program, including the compensation arrangements of our NEOs. The Compensation Committee reviews the types of services provided by Pay Governance and all fees paid for those services on a regular basis. Neither Pay Governance nor any of its affiliates provided additional services to the Company or any of its affiliates in 2025, other than the advice provided by Pay Governance to the Compensation Committee on director compensation, incentive plan design, stock ownership guidelines, and the recovery of erroneously awarded compensation. As required by rules adopted by the SEC under the Dodd-Frank Act, the Compensation Committee assessed all relevant factors and determined that the work of Pay Governance did not raise any conflicts of interest in 2025. In making this determination, the Compensation Committee considered all relevant factors, including those set forth in Rule 10C-1(b)(4)(i) through (vi) under the Exchange Act.

  29. Benchmarking and Individual Considerations

    Benchmarking and Individual Considerations The Company reviews compensation data for similar positions from Proxy peers, as well as from the telecom and networking industry and the broader general industry. We generally seek to provide our executives with base salaries and target bonus and long-term incentive opportunities that are positioned around the median of competitive practice in order to assist in attracting and retaining talented executives and to further motivate and reward our NEOs for sustained, long-term improvements in the Company’s financial results and the achievement of long-term business objectives. We recognize, however, that benchmarking may be subject to variation from one year to the next. As a result, we also use Company and individual performance in determining the appropriate compensation opportunities for our NEOs. Our Compensation Committee focuses on establishing and maintaining a compensation structure that is internally consistent and provides appropriate compensation for our executives in relation to one another. Consequently, the Compensation Committee does not focus on any particular benchmark to set executive compensation. Instead, we believe that a successful compensation program requires the application of judgment and subjective determinations based on the consideration of a number of factors. These factors include the following: • the scope and strategic impact of the executive officer’s responsibilities, including the importance of the job function to our business; • our past financial performance and future expectations; • the performance and experience of each individual; • past salary levels of each individual and of the officers as a group; each individual’s unique capabilities and/or skill set;

  30. Benchmarking and Individual Considerations

    | | 39 | 2026 Proxy Statement |

  31. Benchmarking and Individual Considerations

    the need to provide motivation to officers that is in alignment with stockholder interests, both short- and long-term; and for each executive officer, other than the CEO, the evaluations and recommendations of our CEO. The Compensation Committee does not assign relative weights or rankings to these factors. Our allocation of compensation between cash and equity awards, our two principal forms of compensation, is based upon our historical practice and our evaluation of the cost of equity awards, as discussed in more detail below. An important part of this evaluation is the Committee’s consideration of the goals of the several initiatives undertaken in the execution of the Company’s business plan and each executive’s past and expected future contributions toward those goals at the time of setting executive compensation packages.

  32. Risk Assessment

    Risk Assessment The Compensation Committee has evaluated the Company’s compensation program, plans and practices for all of its employees as they relate to risk management and risk-taking initiatives to ascertain if they serve to incent risks which are “reasonably likely to have a material adverse effect” on the Company. As a result of this process, the Compensation Committee concluded and informed the Board of Directors that any risks arising from these programs, plans and practices are not reasonably likely to have a material adverse effect on the Company. The Compensation Committee has attempted to establish compensation programs that value current goals along with long-term growth. While the use of short-term cash incentive opportunities creates the potential for short-term risk-taking, the Committee believes that this risk is more than offset by the fact that a short-term cash incentive is only one of three primary elements of the overall compensation program and has governance features that are aligned with market best practice (e.g., maximum payout opportunity of 200% of target). Additionally, the Committee has the ability to utilize discretion to reduce the amount of a cash incentive award if an executive officer takes unnecessary risks. The Committee has concluded that the two other primary elements of our total compensation program – base salaries and long-term equity awards – are either risk neutral or help lower risk. Annual salaries are based on a number of factors, including the individual’s position and responsibility within our Company and performance in that position. The longer-term equity awards incentivize executives to focus on improving the Company and its operations rather than taking risks for short-term gain.

  33. Elements of 2025 Executive Compensation

    Elements of 2025 Executive Compensation Our executive compensation program consists of base salary; short-term cash incentives, including those under our VICC program, a sales incentive arrangement for our Chief Revenue Officer, and occasional one-time performance bonuses for certain executives; and long-term equity incentives in the form of time-based and performance-based equity. Historically, the Compensation Committee has granted time-based RSUs that vest ratably over four years and market-based PSUs that the NEOs are eligible to earn based on Company performance over a three-year performance period (collectively, the “Annual Equity Awards”). Additionally, in 2025, the Compensation Committee granted performance-based PSUs to Mr. Stanton that are eligible to be earned based on a financial performance measure over a one-year performance period, consistent with the 2023 Long-Term Financial Plan adopted by the Committee in 2023. The Committee did not grant the NEOs any integration awards or stock options in 2025. The NEOs did, however, remain eligible to earn previously granted performance-based PSUs (based on a financial performance measure over a three-year performance period pursuant to the 2023 Long-Term Financial Plan). In addition, our U.S.-based NEOs are eligible to participate in certain benefit programs that are generally available to all of our U.S.-based employees, such as medical insurance programs, life and disability insurance programs and our 401(k) plan. Our U.S.-based NEOs were also previously eligible to participate in the Company’s Deferred Compensation Plan; however, the Company terminated the Deferred Compensation Program in November 2025. Christoph Glingener, Chief Technology Officer of the Company and former CEO of Adtran Networks, became an executive officer of the Company on September 1, 2022 in connection with the business combination pursuant to which ADTRAN, Inc. and Adtran Networks became subsidiaries of the Company (the "Business Combination"). In accordance with his service agreement, Dr. Glingener's compensation is determined each year by the Adtran Networks supervisory board (which is similar to the board of directors of a U.S. company) in its sole discretion, but the supervisory board takes into account recommendations from the Company’s Compensation Committee. The stockholders of Adtran Networks must also approve Dr. Glingener's underlying compensation framework. See “Employment Arrangements” below for additional detail regarding this service agreement. Additionally, Ulrich Dopfer became an executive officer of the Company on May 1, 2023, in connection with his appointment as Senior Vice President and Chief Financial Officer of the Company, and he subsequently was appointed as the Company’s principal accounting officer and Corporate Secretary and Treasurer on May 10, 2023. On March 6, 2025, the Company and Ulrich Dopfer agreed that Mr. Dopfer would no longer serve as the Company’s Chief Financial Officer, Secretary, Treasurer and principal accounting officer, effective March 10, 2025. Prior to his departure from the Company, Mr. Dopfer was party to a service agreement similar to Dr. Glingener's agreement. Upon the execution of a settlement agreement in May 2025, Mr. Dopfer resigned from all of his positions with the Company and was released from his duties under his service agreement; however, the service agreement remained in force until November 30, 2025. Mr. Dopfer continued to receive his base salary through December 31, 2025. In addition, Mr. Dopfer's unvested RSUs, PSUs and stock options continued to vest as scheduled through November 30, 2025, and all such equity awards that remained unvested or unearned, as applicable, as of November 30, 2025 were forfeited. Mr. Dopfer's short-term cash bonus under the VICC for 2025 was also forfeited. Base Salary Base salaries are integral to any competitive employment arrangement. At the beginning of each fiscal year, the Compensation Committee establishes an annual base salary for our executive officers based on recommendations made by our CEO with respect to the salaries of our other executives. Consistent with our compensation objectives and philosophy described above, the Compensation Committee sets base salary compensation, and adjusts it when warranted, based on the Company’s financial performance, the individual’s position and responsibility within our Company and performance in that position, the importance of the executive’s position to our business, and the compensation of other executive officers of the Company with comparable qualifications, experience and responsibilities. The Committee also generally takes into account the range of salaries of executive officers with comparable qualifications, experience and responsibilities at other companies with which we compete for executive talent.

  34. 2025 Bonus Program

    2025 Bonus Program We provide our executive officers, including our NEOs, with the opportunity to earn short-term cash incentive compensation under our bonus programs, including our VICC. The VICC program is designed to motivate and reward executives for their contribution to the Company’s performance during the fiscal year. A significant portion of the total cash compensation that our executive officers are eligible to receive each year is paid through this program and thus is dependent upon corporate performance. On January 24, 2025, the Compensation Committee established the VICC program for 2025 and set the VICC targets for all NEOs other than Mr. Santo, whose VICC targets were determined in connection with his appointment as Senior Vice President of Finance, Chief Financial Officer and Treasurer of the Company effective March 10, 2025 (pro rated for the length of his employment with the Company in 2025). The Committee chose to base the VICC program for 2025 on two measures of the Company’s financial and operating performance in 2025 (collectively, the “Company Performance Measures”): the Company’s “Adjusted EBIT” (defined as the Company’s earnings before interest and tax, determined based on the Company’s audited financial results, and adjusted to remove any restructuring expenses; acquisition-related expenses and amortization of intangibles; stock-based compensation expense; the non-cash change in fair value of equity investments held in the Deferred Compensation Plan; and any other non-GAAP exclusions approved by the Compensation Committee) and the Company’s revenue. The Compensation Committee continued to utilize the Company Performance Measures in the 2025 VICC program because we consider these measures to be the most appropriate drivers of stockholder value.

  35. 2025 Bonus Program

    | | 42 | 2026 Proxy Statement |

  36. 2025 Bonus Program

    Each NEO was granted a target bonus amount (in dollars and as a percentage of base salary), with the actual incentive earned to be based on the two Company Performance Measures. In determining the target bonus amount for each NEO, the Compensation Committee considered, among other things, the executive’s responsibilities and opportunity to influence the achievement of the Company Performance Measures, as well as the executive’s prior contributions to the Company’s performance. Each NEO’s target bonus amount (in dollars and as a percentage of base salary) was as follows: Mr. Stanton – $1,442,000 (140%), Mr. Santo – $224,581 (60% of Mr. Santo's pro-rated salary), Mr. Dopfer – $246,000 (60%), Mr. Wilson – $166,890 (40%), and Dr. Glingener – $230,799 (60%). The bonus awards for 2025 were based on the two Company Performance Measures described above: Adjusted EBIT: If the threshold Adjusted EBIT was achieved, the participant would earn 15% of the target award. If the target Adjusted EBIT of $20 million was achieved, the participant would earn 50% of the target award. If the maximum Adjusted EBIT was achieved, the participant would earn 100% of the target award. • Revenue: If the threshold revenue level was achieved, the participant would earn 15% of the target award. If the target revenue level of $1 billion was achieved, the participant would earn 50% of the target award. If the maximum revenue level was achieved, the participant would earn 100% of the target award. Payouts for performance between the threshold and maximum levels were subject to linear interpolation between threshold, target and maximum performance levels. Failure to meet the minimum performance threshold corresponding to a specific performance measure would have resulted in the participant not receiving any portion of the payout award related to such performance measure. In no event could a participant receive more than 100% of the target bonus related to each Company Performance Measure and, therefore, not more than 200% of the target bonus award. The Compensation Committee believes that it is appropriate to establish a maximum payout that any participant could receive under the bonus programs in order to avoid an excessive payout should Company results or individual performance significantly exceed expectations.

  37. 2025 Actual Bonus Program Results

    2025 Actual Bonus Program Results The individual target bonus awards, including as a percentage of salary, for the NEOs and the amounts earned and paid in 2025 based on the level of achievement of the Company Performance Measure were as follows:

  38. 2025 Actual Bonus Program Results

    | Named Executive Officer | Target Cash Award as a % of Salary | Target Cash Award Amount ($) | Total Annual Cash Award Earned and Paid in 2025 ($) | Total Cash Award Paid as a % of Target | | Thomas R. Stanton | 140% | 1,442,000 | 2,884,000 | 200% | | Timothy Santo | 60% | 224,581 | 449,162 | 200%(1) | | Ulrich Dopfer | 60% | 246,000 | — | —(2) | | James D. Wilson, Jr. | 40% | 166,890 | 333,779 | 200% | | Christoph Glingener | 60% | 230,799 | 461,598 | 200% |

  39. 2025 Actual Bonus Program Results

    (1) Mr. Santo's bonus was pro-rated for the length of his employment with the Company during 2025. (2) On March 6, 2025, the Company and Mr. Dopfer agreed that Mr. Dopfer would no longer serve as the Company’s Chief Financial Officer, Secretary, Treasurer and principal accounting officer, effective March 10, 2025. Pursuant to a settlement agreement executed by the parties in May 2025, Mr. Dopfer's short-term cash bonus under the VICC for 2025 was forfeited.

  40. 2025 Sales Incentive Arrangement for Chief Revenue Officer

    for sales-oriented executives. Based on input from the CEO, the Compensation Committee approved a target sales incentive for Mr. Wilson in 2025 of $83,445, which is a percentage of his base salary. Mr. Wilson was eligible to receive this target if the Company achieved its net revenue performance target, which was set at a level that the Compensation Committee believes was reasonably difficult to achieve given the business environment at the time the target was established. Mr. Wilson must be an active employee or contractor of the Company at the time of payment in order to receive such amounts. If his employment by or service to the Company is terminated for any reason prior to payment, certain unpaid amounts will be forfeited. The Company’s CEO has discretion to determine that a “windfall” has occurred and decrease the amount paid to Mr. Wilson, and incentive compensation may be reduced or eliminated in order to reflect a number of actions that may be taken by a customer, including canceling or reducing an order or not paying an invoice. Based on this arrangement, Mr. Wilson earned a sales incentive of $83,959 in 2025. Long-Term Incentive Awards Historically, we have compensated our executive officers, including our NEOs, with annual equity awards granted under the ADTRAN Holdings, Inc. 2020 Employee Stock Incentive Plan (as amended and restated, the “2020 Employee Plan”), which was replaced by the ADTRAN Holdings, Inc. 2024 Employee Stock Incentive Plan (the “2024 Employee Plan”) upon its approval by the stockholders at the 2024 Annual Meeting of Stockholders. These equity grants serve to align management’s interests and compensation with the long-term interests of stockholders and provide an incentive for them to maintain their relationship with the Company. See “Equity Compensation Plans—2024 Employee Stock Incentive Plan” beginning on page 58 for a description of our 2024 Employee Plan. The purpose of the 2024 Employee Plan is to provide equity as a component of executive compensation to ensure competitiveness of our compensation program, to motivate our NEOs and other executives to focus on long‑term Company performance, to align executive compensation with stockholder interests and to retain the services of the executives during the vesting period since, in most circumstances, the awards will be forfeited if the executive’s employment terminates before the award vests. The Compensation Committee typically grants 50% of the Annual Equity Awards in the form of time-based RSUs that vest ratably over four years and 50% in the form of market-based PSUs that the NEOs are eligible to earn based on Company performance over a three-year performance period. Additionally, in 2025, the Compensation Committee granted Mr. Stanton performance-based PSUs that are eligible to be earned based on a financial performance measure over a one-year performance period pursuant to the 2023 Long-Term Financial Plan. Below is a summary of the Annual Equity Awards granted to certain of the NEOs on January 24, 2025 (except as noted below) and the performance-based PSUs pursuant to the 2023 Long-Term Financial Plan granted to Mr. Stanton on March 11, 2025, with details regarding such awards following the table:

  41. 2025 Sales Incentive Arrangement for Chief Revenue Officer

    | Named Executive Officer | Target Dollar Value of Annual Time- Based RSUs ($) | Target Dollar Value of Annual Market- Based PSUs ($) | Total Dollar Value of Annual Equity Grants (and % of Base Salary) (1) ($) | Dollar Value of Performance- Based PSUs (2) ($) | Total Dollar Value of 2025 Equity Grants ($) | | Thomas R. Stanton | 1,648,002 | 1,236,004 | 2,884,006 (282%) | 614,091(3) | 3,498,097 | | Timothy Santo(4) | 183,996 | 183,996 | 367,992 (98%) | — | 367,992 | | Ulrich Dopfer(5) | 168,919 | 168,919 | 337,838 (82%) | — | 337,838 | | James D. Wilson, Jr. | 146,031 | 146,031 | 292,062 (71%) | — | 292,062 | | Christoph Glingener | 143,010 | 143,010 | 286,020 (74%) | — | 286,020 |

  42. 2025 Sales Incentive Arrangement for Chief Revenue Officer

    2025 Annual Equity Awards: The total annual equity award granted to each NEO in 2025 was based on a value derived from a percentage of the executive’s base salary. Each NEO other than Mr. Stanton received 50% of his Annual Equity Award in time-based RSUs and 50% of his Annual Equity Award in market-based PSUs, with the number of RSUs or PSUs calculated by dividing the dollar amount of such compensation by an amount equal to the closing price of our common stock on the grant date. With respect to Mr. Stanton, 57.1% of his Annual Equity Award was awarded as time-based RSUs and 42.9% of his Annual Equity Award was awarded as market-based PSUs; however, in looking at the total equity incentive awards granted to Mr. Stanton in 2025 (including the equity granted pursuant to the 2023 Long-Term Financial Plan discussed below), 47.1% of his equity was time-based and 52.9% was performance-based.

  43. 2025 Sales Incentive Arrangement for Chief Revenue Officer

    The Compensation Committee’s process for determining the amounts of the incentive equity awards begins with a consideration of the overall dollar level of value that the Committee determines is appropriate, taking into account the estimated expense to the Company of the awards and the earnings per share impact of that expense. The Committee typically establishes an internal target for the aggregate expense from Company-wide equity awards, which, based on our review of industry data as discussed above, we believe is at the low end of the expense levels incurred by our competitors. This dollar value is then translated into a number of shares of the Company’s common stock based on the current range of the stock’s market price. Based on this process, the Committee established a pool of up to 1,209,145 RSUs and PSUs to be granted to all participants in the 2024 Employee Plan for the 2025 Annual Equity Awards. The 481,701 RSUs and PSUs granted to the NEOs in 2025 are included in this total. The Compensation Committee's delegate allocated the pool of RSUs and PSUs among the different functions throughout the Company based on the importance and performance of the function and considerations such as retention and competitive compensation levels. The Committee also considered the recommendations of our CEO with respect to the awards to other executives and employees. (a) 2025 Time-Based RSUs: The time-based RSUs granted to our NEOs in 2025 vest over four years, with 25% vesting on each of the four anniversaries of the grant date. Vesting is subject to the NEO continuing to be employed on the applicable vesting date and the time-based RSUs are settled through the delivery of one share of common stock for each vested RSU. Mr. Dopfer's prior service agreement contained and Dr. Glingener’s current service agreement contains a provision limiting the value of time-based RSUs vesting on a particular date to three times the value of such time-based RSUs on the grant date (with any excess time-based RSUs over such limitation to be forfeited as of the vesting date). Mr. Dopfer's service agreement terminated as of November 30, 2025. (b) 2025 Market-Based PSUs: The number of shares that the NEOs can earn under the market-based PSUs is based on our relative TSR against a peer group over a three-year performance period starting on the grant date. For the 2025 market-based PSUs, the Compensation Committee chose to continue to use the companies in the Nasdaq Telecommunications Index as the peer group for TSR measurement purposes. The Committee chose this index based on the fact that it contains a significant number of companies and is a broad sample of our industry. Assuming the threshold level of performance is attained, the NEOs are eligible to earn a number of shares between 25% and 150% of their target market-based PSUs based on the Company’s relative TSR performance, based on the sliding scale shown below (approximately 3.0% of the target award is earned for each 1 percentile increase up to 100% of the target award and then approximately 2.0% of the target award is earned for each 1 percentile increase up to 150% of the target award). However, there is a 100% payout cap when our TSR out-performs the Nasdaq Telecommunications Index, but our TSR is negative:

  44. 2025 Sales Incentive Arrangement for Chief Revenue Officer

    | Adtran’s TSR Performance Relative to its Peer Group (expressed as a percentile) | Market-Based PSUs Earned (expressed as a percentage of target) | | Less than 30th percentile | —% | | 30th percentile | 25% | | 35th percentile | 40% | | 40th percentile | 55% | | 45th percentile | 70% | | 50th percentile | 85% | | 55th percentile | 100% | | 60th percentile | 110% | | 65th percentile | 120% | | 70th percentile | 130% | | 75th percentile | 140% | | 80th or more percentile | 150% |

  45. 2025 Sales Incentive Arrangement for Chief Revenue Officer

    Pursuant to earned market-based PSUs, a corresponding number of shares is issued at the end of the three-year performance period, and after that time there is no additional holding period for the shares that are issued. Prior to the suspension of the Company’s dividend, the recipients of the market-based PSUs under the award agreements received dividend credits based on the shares of common stock underlying the market-based PSUs. The dividend credits are vested, earned and distributed in cash upon issuance of the shares pursuant to the earned market-based PSUs. Mr. Dopfer’s prior service agreement contained and Dr. Glingener’s current service agreement contains a provision limiting the value of time-based RSUs vesting on a particular date to three times the value of such time-based RSUs on the grant date (with any excess time-based RSUs over such limitation to be forfeited as of the vesting date). The service agreements also contained a provision limiting the value of earned market-based PSUs to two times the value of such market-based PSUs on the grant date (with any excess market-based PSUs over such limitation to be forfeited as of the end of the performance period). Mr. Dopfer's service agreement terminated as of November 30, 2025. 2023 Long-Term Financial Plan (Three-Year Performance-Based Equity Awards): In each of 2017 and 2020, the Compensation Committee established an equity incentive program aligned with the Company’s long-term strategic plan. The Committee chose to establish the 2023 Long-Term Financial Plan in order to continue to strengthen the alignment between incentives for executives and increases in stockholder value. The 2023 Long-Term Financial Plan consists of one grant or three equal annual grants, as applicable, of performance-based PSUs to our executive officers and certain key employees, including the NEOs. All of the recipients other than Mr. Stanton received one grant of performance-based PSUs under which shares are eligible to be earned at the end of the performance period beginning on the grant date and ending on December 31, 2025. On March 1, 2023, Mr. Stanton received a grant of performance-based PSUs with a three-year performance period (the 2023 grant); on

  46. 2025 Sales Incentive Arrangement for Chief Revenue Officer

    March 1, 2024, he received a grant of performance-based PSUs with a two-year performance period (the 2024 grant); and on March 11, 2025, Mr. Stanton received a grant of performance-based PSUs with a one-year performance period (the 2025 grant). Assuming the threshold level of performance is attained, the recipients are eligible to earn a number of shares between 50% and 150% of their target performance-based PSUs based on the compound annual growth rate (“CAGR”) of the Company’s Adjusted EBIT (as defined above) over the performance period. The Compensation Committee set the Adjusted EBIT performance target at a level that it believes was reasonably difficult to achieve given the business environment at the time the target was established. Prior to the suspension of the Company’s dividend, the recipients of the performance-based PSUs under the award agreements received dividend credits based on the shares of common stock underlying the performance-based PSUs. The dividend credits are vested, earned and distributed in additional shares upon issuance of the shares pursuant to the earned performance-based PSUs. Mr. Dopfer’s prior service agreement contained and Dr. Glingener’s current service agreement contains a provision limiting the value of earned performance-based PSUs to two times the value of such performance-based PSUs on the grant date (with any excess performance-based PSUs over such limitation to be forfeited as of the end of the performance period). Mr. Dopfer's service agreement terminated as of November 30, 2025. As described in footnote 2, this is the dollar value of the third of three annual grants to be made to Mr. Stanton under the 2023 Long-Term Financial Plan. The total target dollar value of Mr. Stanton’s three grants under the 2023 Long-Term Financial Plan was $3,600,000, which equated to 216,738 shares using the closing price of our common stock on March 1, 2023. This amount of shares was divided into three awards, such that Mr. Stanton received a grant of 72,246 performance-based PSUs on March 11, 2025. (4) Mr. Santo's employment with the Company began on March 10, 2025, and he received RSUs and market-based PSUs on March 19, 2025. (5) In connection with his departure from the Company, Mr. Dopfer's unvested RSUs and stock options continued to vest, and he remained eligible to earn his market-based PSUs and performance-based PSUs, through November 30, 2025, and all such equity awards that remained unvested or unearned, as applicable, as of November 30, 2025 were forfeited.

  47. Benefits and Perquisites

    Benefits and Perquisites We maintain general broad-based employee benefit plans in which our U.S.-based executives, including the U.S.-based NEOs, participate, such as a medical insurance plan, a 401(k) plan, and life and disability insurance programs. These benefits are provided as part of the basic conditions of employment for all of our eligible employees and, therefore, providing them to our executive officers does not represent a significant incremental cost to us. In addition, we believe that providing these basic benefits is necessary for us to attract talented executives. The 401(k) plan for U.S. employees allows eligible employees to contribute up to 60% of their pre-tax earnings up to the statutory limit prescribed by the Internal Revenue Service. After one year of service, the Company matches a discretionary amount determined by the Board of Directors. In 2025, we matched our U.S. employee contributions equal to 100% of the first 3% contributed and 50% of the next 2% contributed up to a maximum matching contribution of 4%. Dr. Glingener receives certain benefits pursuant to his service agreement, including, but not limited to, accident and liability insurance, and statutory insurances, including compulsory health, and long-term care. In addition, Dr. Glingener receives unemployment pursuant to his service agreement. Mr. Dopfer received similar benefits (excluding unemployment coverage) under his service agreement; however, the service agreement terminated as of November 30, 2025. Under the 401(k) plan in which Mr. Dopfer participated, in 2025, we matched employee contributions equal to 25% of the first 6% contributed up to a maximum matching contribution of 1.5%. Mr. Dopfer previously vested in the Company’s contributions over five years. Finally, Adtran Networks makes an additional matching contribution (between 15% and 50%) based on the entity’s achievement against an annual earnings goal. We previously maintained a Deferred Compensation Plan for our U.S.-based executives employed by ADTRAN Holdings, Inc., which is described under the Nonqualified Deferred Compensation table below. This plan permitted U.S.-based executives employed by ADTRAN Holdings, Inc., including NEOs, to voluntarily defer a portion of their income and equity awards and save money for retirement on a tax-deferred basis. Although the plan permitted discretionary employer contributions, we did not make any contributions to it. The plan was terminated on November 3, 2025 in an effort to streamline the benefits offered to members of management and other key employees. As described in more detail under “Potential Payments Upon Termination or Change of Control” below, we provide certain benefits to participants in our equity incentive plans and our VICC program, including the NEOs, upon a change of control or upon termination of employment for specified reasons (provided, in some cases, that termination must be a “separation from service” as defined in Section 409A of the Internal Revenue Code). Each of Mr. Stanton’s and Dr. Glingener’s employment and service agreements, as applicable, also provide for certain benefits upon some or all of these events.

  48. Employment Agreement with Mr. Stanton

    Employment Agreement with Mr. Stanton On July 13, 2022, the Company entered into an employment agreement (as amended, the “Employment Agreement”) with the Company’s President, CEO and Chairman, Thomas R. Stanton. Pursuant to the terms of the Employment Agreement, during the term of Mr. Stanton’s employment, Mr. Stanton will serve as the President, CEO and Chairman of the Board of the Company. The Employment Agreement provides for an initial period of employment of two years, which period will automatically renew for successive one-year periods thereafter unless either party provides prior written notice. The Employment Agreement provided for an initial base salary of $875,000 and provides that Mr. Stanton is eligible to receive an annual cash incentive bonus award with a target of at least 140% of his base salary based on the achievement of performance objectives set by the Compensation Committee. He is also eligible to participate in all executive benefit plans made available to similarly situated executive officers of the Company and will be reimbursed for his reasonable out-of-pocket business expenses. In addition, under the terms of the Employment Agreement, Mr. Stanton is entitled to participate in the Company’s equity incentive programs during the term of employment. In 2025, Mr. Stanton was eligible to receive from the Company a combination of PSUs (with the performance objective of such PSUs to be based on the Company’s relative TSR over a three-year performance period or such other performance criteria as shall be mutually agreed upon by Mr. Stanton and the Compensation Committee) and time-based RSUs, on such terms as are provided for in the Employment Agreement. Additionally, Mr. Stanton is entitled to receive PSUs (with the performance objective of such PSUs to be based on the Company’s Adjusted EBIT or such other performance criteria as shall be mutually agreed upon by Mr. Stanton and the Compensation Committee pursuant to the Company’s Long-Term Financial Plan), on such terms as are provided for in the Employment Agreement. The Employment Agreement provides that any such PSU award pursuant to the Long-Term Financial Plan will be subdivided into three equal tranches, with Mr. Stanton eligible to receive one-third of the award each year (with the total target number of PSUs to be calculated on the date of grant of the first tranche of such award). Under the terms of the Employment Agreement, Mr. Stanton is eligible for specified termination payments and benefits in the event of a termination of Mr. Stanton’s employment (i) due to his death or disability, (ii) by Mr. Stanton for good reason, by the Company without cause, or upon a non-renewal of the term of employment by the Company at the completion of the initial two-year term of employment, (iii) due to Mr. Stanton’s retirement (age 65 or age 55 and ten years of service) or (iv) in the event of a termination of employment by the Company without cause or by Mr. Stanton for good reason within two years following a change of control of the Company (excluding the Business Combination), subject to his execution and non-revocation of a release of claims in the Company’s favor and his compliance with confidentiality, non-competition, non-solicitation, non-disparagement and other covenants, all as more specifically provided for in the Employment Agreement and described below under “Potential Payments Upon Termination or Change of Control.”

  49. Employment Agreement with Mr. Stanton

    | | 47 | 2026 Proxy Statement |

  50. Service Agreements with Mr. Dopfer and Dr. Glingener

    Service Agreements with Mr. Dopfer and Dr. Glingener On April 1, 2006, Adtran Networks entered into a service agreement with Christoph Glingener, the former CEO of Adtran Networks and current Chief Technology Officer of the Company, a position he has held since September 1, 2022. Dr. Glingener's service agreement is extended by amendment each year. Pursuant to such agreement, Dr. Glingener's compensation each year is determined by the Adtran Networks supervisory board (which is similar to the board of directors of a U.S. company) in its sole discretion, but the supervisory board takes into account recommendations from the Company’s Compensation Committee. Dr. Glingener receives an annual base salary and is also eligible to receive an annual and/or long-term fixed or variable bonus award, as well as certain equity awards, benefits and perquisites. Additionally, under the terms of his service agreement, Dr. Glingener is eligible for specified termination payments and benefits in the event of a termination of his service due to death or inability to work as more specifically provided for in the service agreement and described below under “Potential Payments Upon Termination or Change of Control.” The service agreement also contains non-competition and non-disclosure covenants applicable to Dr. Glingener. On January 28, 2015, Adtran Networks entered into a service agreement with Ulrich Dopfer on substantially the same terms as Dr. Glingener's service agreement described above. Mr. Dopfer became the Senior Vice President and Chief Financial Officer of the Company on May 1, 2023, and he was subsequently appointed the Company’s principal accounting officer and Corporate Secretary and Treasurer on May 10, 2023. On March 6, 2025, the Company and Mr. Dopfer agreed that Mr. Dopfer would no longer serve as the Company’s Chief Financial Officer, Secretary, Treasurer and principal accounting officer, effective March 10, 2025. Upon the execution of a settlement agreement in May 2025, Mr. Dopfer resigned from all of his positions with the Company and was released from his duties under his service agreement; however, the service agreement remained in force until its termination on November 30, 2025. Mr. Dopfer continued to receive his base salary through December 31, 2025. In addition, Mr. Dopfer's unvested RSUs and stock options continued to vest, and he remained eligible to earn his market-based PSUs and performance-based PSUs, through November 30, 2025, and all such equity awards that remained unvested or unearned, as applicable, as of November 30, 2025 were forfeited. Mr. Dopfer's short-term cash bonus under the VICC for 2025 was forfeited.

  51. Clawback Policies

    Clawback Policies The Board previously adopted a policy providing that, in the event the Company is required to prepare an accounting restatement due to material noncompliance with any financial reporting requirement under the securities laws, the Company will recover incentive-based compensation paid to current or former executive officers of the Company during the three years prior to the date as of which the accounting restatement is required, to the extent that any of that compensation was based upon the erroneous data that made the restatement necessary (the “Original Clawback Policy”). Under the Original Clawback Policy, incentive-based compensation includes RSUs, PSUs, and other cash or equity-based compensation awards. To implement this policy, the Board had entered into a clawback agreement with each of the NEOs providing for their agreement to such repayment. In addition, in October 2023, we adopted a Policy for the Recovery of Erroneously Awarded Incentive Based Compensation (the “New Clawback Policy”), in compliance with the requirements of the Dodd-Frank Act, final SEC rules and applicable Nasdaq listing standards, which covers our current and former officers subject to Section 16 of the Exchange Act, including all of our NEOs. Under the New Clawback Policy, if there is a restatement of our financial results, the Company will recover any erroneously awarded incentive compensation from such officers during a three-year lookback period. In connection with the adoption of the New Clawback Policy, the Board approved an amendment and restatement of the Original Clawback Policy, which applies to compensation received prior to October 2, 2023.

  52. Recovery of Erroneously Awarded Compensation

    Recovery of Erroneously Awarded Compensation Recovery Analysis in Connection with the 2023/2024 Restatements On May 20, 2025, the Company filed an Amendment No. 1 to its Annual Report on Form 10-K for the year ended December 31, 2024 (the "Form 10-K/A") in order to, among other items, restate the consolidated financial statements included in its original Annual Report on Form 10-K for the year ended December 31, 2024 ("Fiscal 2024") and its original Annual Report on Form 10-K for the year ended December 31, 2023 ("Fiscal 2023"). Financial information for the interim periods ended March 31, 2024, June 30, 2024 and September 30, 2024 (the “2024 Interim Periods”) were also restated within the Form 10-K/A (such 2024 Interim Periods, collectively with Fiscal 2024 and Fiscal 2023, the “Affected Periods”, and such restatements, the “2023/2024 Restatements”). Pursuant to the New Clawback Policy, the Company has reviewed the incentive-based compensation received by its officers (as defined in Rule 16a-1(f) under the Exchange Act) covered by the New Clawback Policy, which included its CEO and Chairman of the Board, current and former Senior Vice President of Finance and Chief Financial Officer, Chief Technology Officer, and Chief Revenue Officer (collectively, the “Covered Officers”), and determined that the only amounts subject to recovery under the New Clawback Policy were the annual cash incentives awarded under the VICC program in respect of Fiscal 2024 (the “2024 cash bonuses”), which were subject to financial reporting measure-based vesting conditions that were achieved during Fiscal 2024. The Company did not award any VICC program bonuses to its officers in 2023 since the performance thresholds were not achieved during 2023. Consequently, the Company has determined that the 2023/2024 Restatements did not result in the recoupment of any 2023 incentive compensation under the New Clawback Policy. With respect to the 2024 cash bonuses, each Covered Officer was granted a target bonus amount (in dollars and as a percentage of base salary), with the actual incentive earned being based on Adjusted EBIT and revenue (together, the "Company Performance Measures"). Failure to meet the minimum performance threshold corresponding to a specific Company Performance Measure results in the Covered Officer not receiving any portion of the payout award related to such Company Performance Measure. While the 2023/2024 Restatements did not affect the Company's revenue in 2024, the Company has determined that the 2023/2024 Restatements resulted in a lower Adjusted EBIT in 2024. As a result, a portion of the 2024 cash bonuses received by each of the officers was erroneously awarded and was subject to recovery under the New Clawback Policy. Specifically, Adjusted EBIT for 2024 was previously determined by the Compensation Committee to be $3,227,000 and, following the 2023/2024 Restatements, was determined to be $(2,904,000). The consequence was a reduction in the level of achievement for the portion of the 2024 cash bonuses that was based on Adjusted EBIT from 9.68% of target to 0% of target. As a result of this reduction, payouts to the Covered Officers of the 2024 cash bonuses that were attributable to Adjusted EBIT were determined by the Compensation Committee to be $0, rather than $195,282, in the aggregate, resulting in erroneously awarded compensation attributable to Adjusted EBIT of $195,282. The erroneously awarded compensation with respect to the 2024 cash bonuses was paid to the Covered Officers in cash, net of tax withholding, in March 2025. The Compensation Committee subsequently recovered the full gross amount of such erroneously awarded compensation from the Covered Officers in accordance with the New Clawback Policy during 2025. No erroneously awarded compensation was outstanding as of December 31, 2025. Furthermore, there is no amount of erroneously awarded compensation that has not yet been determined or was outstanding for 180 days or longer since the date that the Company determined the amount owed by each Covered Officer.

  53. Policy for the Granting of Equity-Based Awards

    Policy for the Granting of Equity-Based Awards The Board and the Compensation Committee view equity-based compensation to be a key factor in incentivizing the future performance of our executives. Consequently, the Company adopted a Policy for the Granting of Equity-Based Awards (“Equity Grant Policy”), which was designed to present a framework of practices and procedures for the granting of equity-based awards by the Company. The Equity Grant Policy provides that the Company shall not grant equity awards to employees (i) within 30 days before the anticipated date on which the Company’s financial results containing key information relating to the Company’s financial figures for the applicable quarterly or annual period are to be released to the public via an ad hoc notification, an earnings release, or a filing with the SEC or (ii) during the period beginning four business days before the filing of a periodic report on Form 10-Q or Form 10-K and ending one business day after the filing or furnishing of such report. Additionally, the Equity Grant Policy provides that the Company shall attempt, when feasible, to avoid granting equity awards to employees during the period beginning four business days before the filing or furnishing of a Current Report on Form 8‑K that discloses material nonpublic information (other than a Current Report on Form 8-K disclosing a material new equity award under Item 5.02(e)) and ending one business day after the filing or furnishing of such report. These same restrictions apply to grants of equity awards to non-employee directors except with respect to initial and annual grants of equity awards to such directors, which occur automatically pursuant to the 2024 Directors Stock Plan. Furthermore, the Equity Grant Policy provides that no equity awards shall be backdated nor shall the timing of the grant of an equity award in relation to the public disclosure of material nonpublic information be manipulated with the purpose of benefiting an award recipient. The grant date of any equity awards approved at a meeting of the Compensation Committee or the Board shall be the date of such meeting and, if approved via written consent, the date of execution. The grant date of any equity award approved by an authorized individual (pursuant to the Compensation Committee’s authority to delegate under the Company’s equity incentive plans) will be the date that the authorized individual approves in writing or by email the grant of such award. The policy further states that all equity awards will be made in accordance with applicable laws and stock exchange listing standards, the Compensation Committee’s Charter and applicable equity plan documents.

  54. Summary Compensation Table

    Summary Compensation Table The following table sets forth, for the fiscal years ended December 31, 2025, 2024, and 2023, the total compensation paid to or earned by each of the Company’s NEOs. Additional information about our executive compensation program, including the terms of the various short-term and long-term incentive awards, can be found in the Compensation Discussion and Analysis contained in this Proxy Statement.

  55. Summary Compensation Table

    | Name and Principal Position | Year | Salary ($) (1) | Stock Awards (2) ($) | Option Awards ($) (3) | Non-Equity Incentive Plan Compensation ($) (4) | All Other Compensation ($) (5) | Total ($) | | Thomas R. Stanton | 2025 | 1,022,685 | 3,763,041 | — | 2,884,000 | 14,000 | 7,683,726 | | Chief Executive Officer | 2024 | 709,589 | 2,130,975 | — | 964,920 | 13,800 | 3,819,284 | | | 2023 | 913,699 | 4,918,164 | — | — | 13,200 | 5,845,063 | | Timothy Santo (6) | 2025 | 374,301 | 407,858 | — | 449,162 | 167,338 | 1,398,659 | | Senior Vice President, Chief Financial Officer and Treasurer | | | | | | | | | Ulrich Dopfer | 2025 | 78,495 | 374,047 | — | — | 351,256 | 803,798 | | Former Senior Vice President, Chief Financial Officer, Corporate Secretary and Treasurer | 2024 | 427,083 | 203,012 | — | 208,091 | 8,334 | 846,520 | | | 2023 | 356,705 | 835,743 | — | — | 12,833 | 1,205,281 | | James D. Wilson, Jr. | 2025 | 414,261 | 323,364 | — | 417,738 | — | 1,155,363 | | Chief Revenue Officer | 2024 | 346,253 | 175,504 | — | 107,320 | — | 629,077 | | | 2023 | 387,593 | 1,626,272 | 50,465 | 59,228 | 13,200 | 2,136,758 | | Christoph Glingener (7) | 2025 | 384,665 | 316,675 | — | 461,598 | 18,984 | 1,181,922 | | Chief Technology Officer | 2024 | 380,390 | 183,551 | — | 205,622 | 18,204 | 787,767 | | | 2023 | 335,377 | 790,543 | — | — | 16,713 | 1,142,633 |

  56. Summary Compensation Table

    (1) Amounts for 2024 and 2023 reflect temporary reductions in base salary for the NEOs (other than Mr. Santo, who joined the Company in 2025) made in connection with the Business Efficiency Program implemented by the Company in late 2023. These reductions ended after approximately nine months, and the salary reductions for Dr. Glingener and Mr. Dopfer were reversed due to German law considerations. The amounts reported for Mr. Dopfer for 2025 reflect the amounts paid by the Company through March 9, 2025. Mr. Dopfer agreed to no longer serve as the Company’s Chief Financial Officer, Secretary, Treasurer and principal accounting officer effective March 10, 2025. (2) Amounts for 2025, 2024 and 2023 include the aggregate grant date fair value of time-based RSUs, market-based PSUs, and performance-based PSUs, each as described below and computed in accordance with the Stock Compensation Topic of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”). For a description of the assumptions used to determine these amounts, see the Stock-Based Compensation note to the consolidated financial statements in our Annual Report on Form 10-K for each of the years ended December 31, 2025, December 31, 2024 (as amended), and December 31, 2023. Amounts do not include phantom stock acquired due to the “reinvestment” of dividends paid on equity deferred under the Company’s equity deferral program, as the amounts of future dividends are factored into the grant date fair value of the awards. Annual Stock Awards: Amounts for 2025, 2024 and 2023 include the aggregate grant date fair value of annual stock awards, including grants of time-based RSUs and market-based PSUs. The grant date fair values of the time-based RSUs are based on the closing price of our common stock on the grant date. The grant date fair values of the market-based PSUs are based on the probable outcome of the performance conditions as of the grant dates (taking into account a Monte Carlo simulation applicable to the market-based performance metric, or $10.95 for the market-based PSUs granted on March 19, 2025, $12.95 for the market-based PSUs granted on January 24, 2025, $8.29 for the market-based PSUs granted on January 26, 2024, and $22.31 for the market-based PSUs granted on January 20, 2023). The maximum values of the market-based PSUs (calculated by multiplying the maximum potential number of market-based PSUs that could be earned by the grant date fair values set forth above) are: for Mr. Stanton, $2,251,422, $1,212,031 and $2,187,239 for the 2025, 2024 and 2023 awards, respectively; for Mr. Santo, $335,793 for the 2025 awards; for Mr. Dopfer, $307,692, $165,651 and $132,372 for the 2025, 2024 and 2023 awards, respectively; for Mr. Wilson, $266,000, $143,201 and $295,329 for the 2025, 2024 and 2023 awards, respectively; and for Dr. Glingener, $260,497, $94,281 and $113,003 for the 2025, 2024 and 2023 awards, respectively. There can be no assurance that the grant date fair value will ever be realized. Long-Term Financial Plan Stock Awards (3-year awards): Amounts for 2025, 2024 and 2023 include the aggregate grant date fair value of the performance-based PSUs granted pursuant to the 2023 Long-Term Financial Plan. The grant date fair values of the performance-based PSUs are based on the closing stock price on the grant date. The maximum values of the performance-based PSUs (calculated by multiplying the maximum potential number of performance-based PSUs that could have been earned by the grant date fair value) are: for Mr. Stanton, $614,091, $629,624, and $1,800,009 for the 2025, 2024 and 2023 awards, respectively; for Mr. Dopfer, $790,191 for the 2023 awards; for Mr. Wilson,

  57. Summary Compensation Table

    | | 52 | 2026 Proxy Statement |

  58. Summary Compensation Table

    $1,500,008 for the 2023 awards; and for Dr. Glingener, $790,191 for the 2023 awards. There can be no assurance that the grant date fair value will ever be realized. Equity Portion of Integration Awards: Amounts for 2023 also include the aggregate grant date fair value of the performance-based PSUs granted pursuant to the Integration Bonus Plan. The grant date fair values of the performance-based PSUs are based on the closing stock price on the grant date. The maximum values of the performance-based PSUs (calculated by multiplying the maximum potential number of performance-based PSUs that could have been earned by the grant date fair value) are: for Mr. Stanton, $659,998; for Mr. Dopfer, $142,546; for Mr. Wilson, $267,355; and for Dr. Glingener, $121,686. This amount represents the grant date fair value of a one-time grant of 16,878 stock options to Mr. Wilson in connection with his salary reduction approved on December 1, 2023, pursuant to the Business Efficiency Program. The grant date fair value is computed in accordance with the Stock Compensation Topic of the FASB ASC. For a description of the assumptions used to determine this amount, see the Stock-Based Compensation note to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2025. There can be no assurance that the grant date fair value will ever be realized. (4) See “Elements of 2025 Executive Compensation—Short-Term Cash Incentives—2025 Bonus Program” above for a description of the annual cash incentive awards granted to the NEOs during 2025. The Company’s annual cash incentive awards are based on pre-established, performance‑based targets and, therefore, are reportable as “Non‑Equity Incentive Plan Compensation” rather than as “Bonus.” For Mr. Wilson, these amounts also include sales incentive payments earned during such years. Furthermore, the 2024 amounts include the cash bonus earned pursuant to the Integration Bonus Plan. See “Elements of 2024 Executive Compensation—Long-Term Cash Incentives—Integration Awards” in the Company's Revised Definitive Proxy Statement filed on June 9, 2025. Amounts in this column for 2024 also exclude erroneously awarded compensation that was subject to recovery under the New Clawback Policy as a result of a restatement of the Company's previously issued financial statements. Moreover, in connection with his departure from the Company, Mr. Dopfer's short-term cash bonus under the VICC for 2025 was forfeited. (5) All Other Compensation for 2025 for each NEO consists of the following:

  59. Summary Compensation Table

    | Name | Company Contributions to 401(k) Plan ($) (a) | Perquisites ($) (b) | Termination Payments ($) (c) | Total ($) | | Thomas R. Stanton | 14,000 | — | — | 14,000 | | Timothy Santo | — | 167,338 | — | 167,338 | | Ulrich Dopfer | 7,801 | 621 | 342,834 | 351,256 | | James D. Wilson, Jr. | — | — | — | — | | Christoph Glingener | — | 18,984 | — | 18,984 |

  60. Summary Compensation Table

    (a) Represents the Company’s contributions in 2025, if any, to each NEO’s 401(k) retirement plan account, other than Dr. Glingener who is not based in the U.S. and is thus not eligible to participate in the 401(k) plan. (b) For Mr. Santo, this amount represents relocation benefits, including a miscellaneous one-time moving expenses allowance ($5,000), reimbursement of certain costs relating to the sale of his prior home and purchase of a new home ($107,380), a rental allowance to cover temporary housing costs ($8,000), and reimbursement of certain moving and storage fees ($46,958). For Mr. Dopfer, this amount represents long-term disability plan premiums. For Dr. Glingener, this amount represents the taxable benefit of his use of a Company car ($7,822) and contributions by the Company toward his German pension insurance ($1,369) and German unemployment insurance ($9,793). Dr. Glingener’s amounts are reflected in the table in U.S. dollars and were converted from Euros to U.S. dollars using the average Euro to U.S. dollar foreign currency exchange rate for 2025, or 1.0901. Prior year amounts for Mr. Stanton have been revised to eliminate the premiums paid for continued additional medical benefits as Mr. Stanton reimburses the Company annually for such amounts. (c) Mr. Dopfer agreed to no longer serve as the Company’s Chief Financial Officer, Secretary, Treasurer and principal accounting officer effective March 10, 2025; however, he remained employed by the Company and continued to serve as a management board member of Adtran Networks until the execution of a settlement agreement in May 2025. In accordance with the terms of the settlement agreement, Mr. Dopfer continued to receive his base salary through December 31, 2025. The termination payment reflects the salary paid to Mr. Dopfer from March 10, 2025 through December 31, 2025. (6) Compensation information is not provided for Mr. Santo for 2024 or 2023 as he joined the Company on March 10, 2025. The amounts included in the table are in U.S. dollars, but Dr. Glingener received his salary in Euros. To convert his Euro amounts to U.S. dollars for the table, we used the average Euro to U.S. dollar foreign currency exchange rate for 2025 (1.0901), 2024 (1.0849), and for 2023 (1.0765).

  61. Summary Compensation Table

    | | 53 | 2026 Proxy Statement |

  62. Grants of Plan-Based Awards in 2025

    Grants of Plan-Based Awards in 2025 The following table provides certain information regarding the annual cash incentive compensation and equity incentive awards granted to our NEOs during the fiscal year ended December 31, 2025. Additional information about our executive compensation program, including the terms of the various short-term and long-term incentive awards, can be found in the Compensation Discussion and Analysis contained in this Proxy Statement.

  63. Grants of Plan-Based Awards in 2025

    | | | Estimated Future Payouts Under Non-Equity Incentive Plan Awards | | | Estimated Future Payouts Under Equity Incentive Plan Awards | | | | | | Name | Grant Date | Threshold ($) | Target ($) | Maximum ($) | Threshold (#) | Target (#) | Maximum (#) | All Other Stock Awards Number of Shares of Stock or Units (#) | Grant Date Fair Value of Stock and Option Awards ($)(1) | | Thomas R. Stanton | 1/24/2025 (2) | — | — | — | 29,971 | 119,884 | 179,825 | — | 1,500,948 | | | 1/24/2025 (3) | — | — | — | — | — | — | 159,845 | 1,648,002 | | | 2/28/2025 (4) | 432,600 | 1,442,000 | 2,884,000 | — | — | — | — | — | | | 3/11/2025 (5) | — | — | — | 36,123 | 72,246 | 108,369 | — | 614,091 | | Timothy Santo | 3/19/2025 (2) | — | — | — | 5,111 | 20,444 | 30,667 | — | 223,862 | | | 3/19/2025 (3) | — | — | — | — | — | — | 20,444 | 183,996 | | | 3/19/2025 (4) | 67,374 | 224,581 | 449,162 | — | — | — | — | — | | Ulrich Dopfer | 1/24/2025 (2) | — | — | — | 4,096 | 16,348 | 24,576 | — | 205,128 | | | 1/24/2025 (3) | — | — | — | — | — | — | 16,384 | 168,919 | | | 2/28/2025 (4) | 73,800 | 246,000 | 492,000 | — | — | — | — | — | | James D. Wilson, Jr. | 1/24/2025 (6) | — | 83,445 | — | — | — | — | — | — | | | 1/24/2025 (2) | — | — | — | 3,541 | 14,164 | 21,246 | — | 177,333 | | | 1/24/2025 (3) | — | — | — | — | — | — | 14,164 | 146,031 | | | 2/28/2025 (4) | 50,067 | 166,890 | 333,780 | — | — | — | — | — | | Christoph Glingener | 1/24/2025 (2) | — | — | — | 3,468 | 13,871 | 20,806 | — | 173,665 | | | 1/24/2025 (3) | — | — | — | — | — | — | 13,871 | 143,010 | | | 2/28/2025 (4) | 69,240 | 214,514 | 429,028 | — | — | — | — | — |

  64. Grants of Plan-Based Awards in 2025

    (1) The values shown in this column represent the grant date fair values of the various awards as described below. For a description of the assumptions used to determine these amounts, see the Stock-Based Compensation note to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2025. With respect to the market-based PSUs, the grant date fair value of the target award is calculated by multiplying the target number of market-based PSUs by an amount based on the probable outcome of the performance conditions as of the grant date, using a Monte Carlo simulation, or $12.52 for the market-based PSUs granted to the named executive officers other than Mr. Santo on January 24, 2025 and $10.95 for the market-based PSUs granted to Mr. Santo on March 19, 2025 . With respect to the time-based RSUs, the grant date fair value of the award is based on the closing stock price on the grant date. With respect to the performance-based PSUs granted to Mr. Stanton pursuant to the 2023 Long-Term Financial Plan, the grant date fair value of the target award is calculated by multiplying the target number of performance-based PSUs by the closing stock price as of the grant date, or $8.50 for the performance-based PSUs granted on March 11, 2025. There can be no assurance that the grant date fair value will ever be realized. (2) Annual Stock Awards (Market-Based PSUs): The amounts shown in this row reflect the threshold, target and maximum amounts potentially payable to each NEO under the market-based PSU awards granted on January 24, 2025 or, for Mr. Santo, March 19, 2025. (3) Annual Stock Awards (Time-Based RSUs): The amounts shown in this row reflect the number of time-based RSUs granted to each NEO on January 24, 2025 or, for Mr. Santo, March 19, 2025. (4) 2025 Bonus Program: The amounts shown in this row reflect the threshold, target and maximum amounts potentially payable to each NEO under our bonus program in 2025. The actual amount earned in 2025 by each NEO under the 2025 bonus program is reflected in the “Non-Equity Incentive Plan Compensation” column of the Summary Compensation Table on page 52. Mr. Santo's bonus was pro-rated based on the length of his employment with the Company in 2025. (5) Long-Term Financial Plan Stock Awards (3-year awards): The amounts shown in this row reflect the threshold, target and maximum amounts potentially payable to Mr. Stanton under the performance-based PSU award granted to him in 2025 pursuant to the 2023 Long-Term Financial Plan. 2025 Sales Incentive Arrangement: Mr. Wilson was also eligible to earn a sales incentive payment during 2025, and his target established by the Compensation Committee was $83,445. There is no threshold or maximum level of sales applicable to this arrangement.

  65. Grants of Plan-Based Awards in 2025

    | | 54 | 2026 Proxy Statement |

  66. Outstanding Equity Awards at 2025 Fiscal Year-End

    Outstanding Equity Awards at 2025 Fiscal Year-End The following table sets forth information regarding all outstanding equity awards held by our NEOs as of December 31, 2025.

  67. Outstanding Equity Awards at 2025 Fiscal Year-End

    | | | Option Awards | | | | Stock Awards | | | | | Name | Grant Date | Number of Securities Underlying Unexercised Options (#) Exercisable (1) | Number of Securities Underlying Unexercised Options (#) Unexercisable (1) | Option Exercise Price ($) (2) | Option Expiration Date | Number of Shares or Units of Stock That Have Not Vested (#)(3) | Market Value of Shares or Units of Stock That Have Not Vested ($) (4) | Equity Incentive Plan Awards: Number of Unearned Shares, Units or Other Rights That Have Not Vested (#)(5) | Equity Incentive Plan Awards: Market or Payout Value of Unearned Shares, Units or Other Rights That Have Not Vested ($) (4) | | Thomas | 1/20/2023 | — | — | — | — | 43,573 | 378,658 | — | — | | R. Stanton | 1/20/2023 | — | — | — | — | — | — | 65,359 | 567,970 | | | 1/26/2024 | — | — | — | — | 97,469 | 847,006 | — | — | | | 1/26/2024 | — | — | — | — | — | — | 146,204 | 1,270,508 | | | 1/24/2025 | — | — | — | — | 159,845 | 1,389,053 | — | — | | | 1/24/2025 | — | — | — | — | — | — | 119,884 | 1,041,792 | | Timothy | 3/19/2025 | — | — | — | — | 20,444 | 177,658 | — | — | | Santo | 3/19/2025 | — | — | — | — | — | — | 20,444 | 177,658 | | Ulrich | 5/15/2021 | 61,830 | — | 12.17 | 2/28/2026 | — | — | — | — | | Dopfer | | | | | | | | | | | James D. | 1/20/2023 | — | — | — | — | 4,413 | 38,349 | — | — | | Wilson, Jr. | 1/20/2023 | — | — | — | — | — | — | 8,825 | 76,689 | | | 12/1/2023 | 16,878 | — | 5.23 | 12/1/2033 | — | — | — | — | | | 1/26/2024 | — | — | — | — | 8,637 | 75,056 | — | — | | | 1/26/2024 | — | — | — | — | — | — | 17,274 | 150,111 | | | 1/24/2025 | — | — | — | — | 14,164 | 123,085 | — | — | | | 1/24/2025 | — | — | — | — | — | — | 14,164 | 123,085 | | Christoph | 5/15/2020 | 41,220 | — | 7.01 | 5/14/2027 | — | — | — | — | | Glingener | 5/15/2021 | 107,172 | — | 12.17 | 5/14/2028 | — | — | — | — | | | 5/15/2022 | — | 85,383 | 19.08 | 5/14/2029 | — | — | — | — | | | 5/24/2023 | — | — | — | — | 3,813 | 33,135 | — | — | | | 5/24/2023 | — | — | — | — | — | — | 7,625 | 66,261 | | | 1/26/2024 | — | — | — | — | 9,033 | 78,497 | — | — | | | 1/26/2024 | — | — | — | — | — | — | 18,066 | 156,994 | | | 1/24/2025 | — | — | — | — | 13,871 | 120,539 | — | — | | | 1/24/2025 | — | — | — | — | — | — | 13,871 | 120,539 |

  68. Outstanding Equity Awards at 2025 Fiscal Year-End

    (1) Mr. Dopfer’s and Dr. Glingener’s stock options were granted prior to the Business Combination pursuant to the 2011 ADVA Optical Networking SE Stock Option Right Program for the Management Board, Plan XIVa (the “2011 ADVA Optical Networking Stock Option Program”) and were assumed by the Company in the Business Combination, such that they are now exercisable for Company common stock. In connection with this assumption, the assumed options are subject to the terms and conditions of the 2015 Employee Plan, except with respect to the vesting and expiration terms, which continue to be governed by the 2011 ADVA Optical Networking Stock Option Program. Mr. Dopfer’s and Dr. Glingener’s stock options became exercisable or, with respect to Dr. Glingener's stock options granted on May 15, 2022, will become exercisable on the fourth anniversary of the execution of the applicable award agreement and expire seven years from such date of execution or 90 days following such individual's termination of employment. Mr. Wilson received a one-time grant of stock options under the 2020 Employee Plan in connection with his salary reduction approved on December 1, 2023 pursuant to the Business Efficiency Program. These stock options vest in equal installments over two years from the grant date. (2) For Mr. Dopfer and Dr. Glingener, the option exercise price presented was calculated by dividing the exercise price of the applicable Adtran Networks stock option immediately prior to the closing of the Business Combination by the exchange ratio applicable to the Business Combination, converted into U.S. dollars at the applicable foreign exchange rate on the date of the closing. (3) The time-based RSUs granted under the 2020 Employee Plan and the 2024 Employee Plan vest 25% on each of the first four anniversaries of the grant date. The market value is based on the closing price of our common stock on Nasdaq on December 31, 2025, the last trading day of 2025, of $8.69, multiplied by the number of unvested time-based RSUs or unearned PSUs, as applicable. With respect to the market-based PSUs, the reported value of each award has been presented based on the assumed achievement of the next higher performance measure that exceeds actual performance as of December 31, 2025.

  69. Outstanding Equity Awards at 2025 Fiscal Year-End

    | | 55 | 2026 Proxy Statement |

  70. Outstanding Equity Awards at 2025 Fiscal Year-End

    Recipients are eligible to earn the market-based PSUs granted pursuant to the Annual Equity Awards based on the Company’s relative TSR performance over a three-year performance period from the grant date. The number of shares for each award has been presented based on the assumed achievement of the next higher performance measure that exceeds actual performance as of December 31, 2025.

  71. Outstanding Equity Awards at 2025 Fiscal Year-End

    | | 56 | 2026 Proxy Statement |

  72. Option Exercises and Stock Vested in 2025

    Option Exercises and Stock Vested in 2025 The following table sets forth information with respect to PSUs that were earned and time-based RSUs that vested during the fiscal year ended December 31, 2025. None of the NEOs exercised stock options during the fiscal year ended December 31, 2025.

  73. Option Exercises and Stock Vested in 2025

    | | Stock Awards | | | Name | Number of Shares Acquired on Vesting (#) (1) | Value Realized on Vesting ($) (2) | | Thomas R. Stanton | 100,143 | 954,970 | | Timothy Santo | — | — | | Ulrich Dopfer | 5,563 | 51,750 | | James D. Wilson, Jr. | 6,679 | 63,846 | | Christoph Glingener | 4,917 | 45,910 |

  74. Option Exercises and Stock Vested in 2025

    (1) Represents (i) the time-based RSUs that vested in 2025, which RSUs vest 25% on each of the first four anniversaries of the respective grant date and (ii) the market-based PSUs earned in 2025. While the performance period ended for the 2023 Long-Term Financial Plan PSUs on December 31, 2025, the performance threshold was not achieved and the NEOs did not receive any shares upon the settlement of such PSUs. (2) The value realized upon the vesting of the time-based RSUs is calculated based upon the closing price of our common stock on Nasdaq on the applicable vesting dates. The value realized upon the issuance of the earned PSUs is calculated based upon the closing price of our common stock on Nasdaq on December 31, 2025, of $8.69.

  75. Nonqualified Deferred Compensation in 2025

    Nonqualified Deferred Compensation in 2025 The following table sets forth information regarding the deferred compensation plans in which our NEOs participated in 2025.

  76. Nonqualified Deferred Compensation in 2025

    | Name | Executive Contributions in Last FY ($) | Registrant Contributions in Last FY ($) | Aggregate Earnings in Last FY ($) | Aggregate Withdrawals/ Distributions ($) | Aggregate Balance at Last FYE ($) (1) | | Thomas R. Stanton | — | — | 4,339,829 | — | 32,053,470 | | Timothy Santo | — | — | — | — | — | | Ulrich Dopfer | — | — | — | — | — | | James D. Wilson, Jr. | — | — | 9,557 | — | 173,849 | | Christoph Glingener | — | — | — | — | — |

  77. Nonqualified Deferred Compensation in 2025

    (1) These amounts reflect the following amounts that have been reported as compensation to the NEO in previous proxy statements: Mr. Stanton, $27,713,642, and Mr. Wilson, $164,292. We previously maintained the ADTRAN Holdings, Inc. Deferred Compensation Plan for Employees, the ADTRAN Holdings, Inc. Deferred Compensation Plan for Directors, the ADTRAN Holdings, Inc. Equity Deferral Program for Employees and the ADTRAN Holdings, Inc. Equity Deferral Program for Directors. These four plans were originally a single deferred compensation plan; however, for administrative purposes, we restated that single plan into four separate plans which we refer to herein, collectively, as a single “Deferred Compensation Plan.” The Deferred Compensation Plan was terminated by the Board effective November 3, 2025. The Deferred Compensation Plan was offered as a supplement to our tax-qualified 401(k) plan and allowed participants to defer a portion of their salaries and all or a portion of their annual VICC and equity awards and permitted us to make matching contributions on a discretionary basis, without the limitations that apply to the 401(k) plan. We did not make any matching contributions under the plan. All contributions were unfunded and were credited to bookkeeping accounts for the participants, although we set aside assets in a rabbi trust to pay for the benefits under the Deferred Compensation Plan. Each participant’s account was credited with earnings as if the account were invested as elected by the participant among pre-approved mutual funds. Benefits were usually distributed or began to be distributed on the first day of the month following the six-month anniversary of the participant’s separation from service. Benefits were paid in a single lump sum cash payment, and any deferred stock awards were paid in whole shares of Adtran common stock with fractional shares paid in cash; however, a participant could elect to receive a portion of his or her benefit in installments paid over three or ten years. Under the Deferred Compensation Plan, participants were entitled to receive their benefits upon termination of employment (provided the termination is a “separation from service” as defined in Section 409A of the Internal Revenue Code). The amount they received was based on their account balance, which would consist of their contributions to the plan and any earnings as described above. Benefits were not payable from the plan until the first day of the month following the six-month anniversary of the participant’s separation from service. As a result of the termination of the Deferred Compensation Plan, no new deferrals were permitted to be credited to the participants for compensation earned after November 3, 2025. Due to federal tax law, distributions from the Deferred Compensation Plan that are related to the termination of the Deferred Compensation Plan may only be made after November 3, 2026, and they must be completely distributed by November 3, 2027. The Company intends to distribute the entire vested balance to participants as soon as administratively feasible after November 3, 2026.

  78. Nonqualified Deferred Compensation in 2025

    | | 62 | 2026 Proxy Statement |

  79. Potential Payments Upon Termination or Change of Control

    Potential Payments Upon Termination or Change of Control This section describes the limited benefits that would be provided to our NEOs under our executive compensation arrangements upon a change of control of the Company or following termination of employment (provided, in some cases further described below, the termination must be a “separation from service” as defined in Section 409A of the Internal Revenue Code). We also provide tables below showing the potential benefits payable to each of our NEOs upon a change of control of the Company or following termination of employment as of December 31, 2025.

  80. Employment Agreements and Service Agreements

    Employment Agreements and Service Agreements Mr. Stanton’s Employment Agreement Under the terms of his Employment Agreement, Mr. Stanton is eligible for specified termination payments and benefits in the event of a termination of Mr. Stanton’s employment (i) due to his death or disability, (ii) by Mr. Stanton for good reason, by the Company without cause, or upon a non-renewal of the term of employment by the Company at the completion of the initial two-year term of employment, (iii) due to Mr. Stanton’s retirement (age 65 or age 55 and ten years of service) or (iv) in the event of a termination of employment by the Company without cause or by Mr. Stanton for good reason within two years following a change of control of the Company (excluding the Business Combination), subject to his execution and non-revocation of a release of claims in the Company’s favor and his compliance with confidentiality, non-competition, non-solicitation, non-disparagement and other covenants, all as more specifically provided for in the Employment Agreement.

  81. Employment Agreements and Service Agreements

    | | 64 | 2026 Proxy Statement |

  82. Employment Agreements and Service Agreements

    Mr. Dopfer’s and Dr. Glingener’s Service Agreements Under the terms of their service agreements with Adtran Networks, Mr. Dopfer was and Dr. Glingener is eligible for specified termination payments and benefits in the event of a termination of employment due to death, illness, or inability to work as more specifically provided for in the service agreements. On March 6, 2025, the Company and Mr. Dopfer agreed that Mr. Dopfer would no longer serve as the Company’s Chief Financial Officer, Secretary, Treasurer and principal accounting officer, effective March 10, 2025. Upon the execution of a settlement agreement in May 2025, Mr. Dopfer resigned from all of his positions with the Company and was released from his duties under his service agreement; however, the service agreement remained in force until its termination on November 30, 2025. Mr. Dopfer continued to receive his base salary through December 31, 2025. In addition, Mr. Dopfer's unvested RSUs and stock options continued to vest, and he remained eligible to earn his market-based PSUs and performance-based PSUs, through November 30, 2025, and all such equity awards that remained unvested or unearned, as applicable, as of November 30, 2025 were forfeited. Mr. Dopfer's short-term cash bonus under the VICC for 2025 was forfeited.

  83. Potential Payments for NEOs Who Remain Employed with the Company

    Potential Payments for NEOs Who Remain Employed with the Company The following tables set forth the potential benefits payable to the NEOs (other than Mr. Dopfer) pursuant to the arrangements described above, assuming a termination of employment or a change of control had occurred on December 31, 2025. The tables do not include: (i) compensation or benefits previously earned by the NEOs and paid or equity incentive awards that were already fully vested prior to December 31, 2025; (ii) the amounts payable under the Deferred Compensation Plan that are disclosed in the table titled “Nonqualified Deferred Compensation in 2025” above; or (iii) the value of any benefits (such as retiree health coverage, life insurance and disability coverage) provided on the same basis to substantially all other employees. Additional information applicable to all of the tables quantifying potential benefits for the NEOs includes: • Values of Dr. Glingener’s cash severance payments are expressed in U.S. dollars and have been converted using the average Euro to U.S. dollar foreign currency exchange rate for 2025, or 1.0901. Values of equity-related benefits have been determined based on the closing price of the Company’s common stock on Nasdaq on December 31, 2025, the last trading day of 2025 ($8.69), multiplied by the number of applicable shares.

  84. Potential Payments for NEOs Who Remain Employed with the Company

    | | 65 | 2026 Proxy Statement |

  85. Pay Versus Performance

    Pay Versus Performance In accordance with rules adopted by the SEC pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, we provide the following disclosure regarding executive compensation for our principal executive officer (“PEO”) and Non-PEO NEOs and Company performance for the fiscal years listed below. The Compensation Committee did not consider the pay versus performance disclosure below in making its pay decisions for any of the years shown.

  86. Pay Versus Performance

    | | | | | | Value of Initial Fixed $100 Investment based on: (4) | | | | | Year | Summary Compensation Table Total for PEO (1) ($) | Compensation Actually Paid to PEO (1)(2)(3) ($) | Average Summary Compensation Table Total for Non-PEO NEOs (1) ($) | Average Compensation Actually Paid to Non-PEO NEOs (1)(2)(3) ($) | TSR ($) | Peer Group TSR ($) | Net Income (5) ($ Millions) | Adjusted EBIT (6) ($ Millions) | | 2025 | 7,683,726 | 6,512,255 | 1,134,936 | 993,698 | 62.59 | 117.28 | (36.2) | 51.7 | | 2024 | 3,819,284 | 3,722,509 | 754,455 | 842,050 | 60.00 | 104.62 | (450.1) | (2.9) | | 2023 | 5,845,063 | (3,437,020) | 1,291,473 | (349,239) | 52.87 | 92.14 | (261.9) | (9.9) | | 2022 | 10,467,712 | 9,153,853 | 1,110,338 | 1,053,973 | 131.83 | 80.59 | (8.9) | 52.2 | | 2021 | 4,515,356 | 6,565,639 | 1,155,022 | 1,381,134 | 157.43 | 106.15 | (8.6) | 11.3 |

  87. Pay Versus Performance

    (1) The PEO for each year presented was Thomas R. Stanton. The individuals comprising the Non-PEO NEOs for each year presented are listed below:

  88. Pay Versus Performance

    | 2025 | 2024 | 2023 | 2022 | 2021 | | Timothy Santo | Ulrich Dopfer | Ulrich Dopfer | Michael K. Foliano | Michael K. Foliano | | James D. Wilson, Jr. | James D. Wilson, Jr. | James D. Wilson, Jr. | James D. Wilson, Jr. | James D. Wilson, Jr. | | Christoph Glingener | Christoph Glingener | Christoph Glingener | Ronald D. Centis | Ronald D. Centis | | Ulrich Dopfer | | Michael K. Foliano | Raymond Harris | Raymond Harris | | | | | Christoph Glingener | |

  89. Pay Versus Performance

    (2) The amounts shown for Compensation Actually Paid have been calculated in accordance with Item 402(v) of Regulation S-K and do not reflect compensation actually earned, realized, or received by the Company’s NEOs. These amounts reflect the Summary Compensation Table Total with certain adjustments as described in footnote 3 below. (3) Compensation Actually Paid reflects the exclusions and inclusions of certain amounts for the PEO and the Non-PEO NEOs as set forth below. Equity values are calculated in accordance with FASB ASC Topic 718. Amounts in the Exclusion of Stock Awards column are the totals from the Stock Awards column set forth in the Summary Compensation Table.

  90. Pay Versus Performance

    | Year | Summary Compensation Table Total for Thomas R. Stanton ($) | Exclusion of Stock Awards for Thomas R. Stanton ($) | Inclusion of Equity Values for Thomas R. Stanton ($) | Compensation Actually Paid to Thomas R. Stanton ($) | | 2025 | 7,683,726 | (3,763,041) | 2,591,570 | 6,512,255 | | 2024 | 3,819,284 | (2,130,975) | 2,034,200 | 3,722,509 | | 2023 | 5,845,063 | (4,918,164) | (4,363,919) | (3,437,020) |

  91. Pay Versus Performance

    | | 73 | 2026 Proxy Statement |

  92. Pay Versus Performance

    | Year | Average Summary Compensation Table Total for Non-PEO NEOs ($) | Average Exclusion of Stock Awards for Non-PEO NEOs ($) | Average Inclusion of Equity Values for Non-PEO NEOs ($) | Average Compensation Actually Paid to Non-PEO NEOs ($) | | 2025 | 1,134,936 | (355,486) | 214,248 | 993,698 | | 2024 | 754,455 | (187,356) | 274,951 | 842,050 |

  93. Pay Versus Performance

    The amounts in the Inclusion of Equity Values in the tables above are derived from the amounts set forth in the following tables:

  94. Pay Versus Performance

    | Year | Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for Thomas R. Stanton ($) | Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for Thomas R. Stanton ($) | Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Thomas R. Stanton ($) | Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for Thomas R. Stanton ($) | Fair Value at Last Day of Prior Year of Equity Awards Forfeited During Year for Thomas R. Stanton ($) | Total - Inclusion of Equity Values for Thomas R. Stanton ($) | | 2025 | 2,520,425 | (49,637) | — | 120,782 | — | 2,591,570 | | 2024 | 2,128,124 | 110,113 | — | (204,037) | — | 2,034,200 | | 2023 | 1,346,597 | (4,573,766) | — | (1,136,750) | — | (4,363,919) |

  95. Pay Versus Performance

    | Year | Average Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for Non-PEO NEOs ($) | Average Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for Non-PEO NEOs ($) | Average Vesting- Date Fair Value of Equity Awards Granted During Year that Vested During Year for Non-PEO NEOs ($) | Average Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for Non-PEO NEOs ($) | Average Fair Value at Last Day of Prior Year of Equity Awards Forfeited During Year for Non-PEO NEOs ($) | Total - Average Inclusion of Equity Values for Non-PEO NEOs ($) | | 2025 | 221,884 | 2,340 | — | (9,976) | — | 214,248 | | 2024 | 234,284 | 40,823 | — | (156) | — | 274,951 |

  96. Pay Versus Performance

    (4) The Peer Group TSR set forth in this table utilizes the NASDAQ Telecommunications Index, which we also utilize in the stock performance graph required by Item 201(e) of Regulation S-K included in our Annual Report for the year ended December 31, 2025. The comparison assumes $100 was invested for the period starting December 31, 2020, through the end of the listed year in the Company and in the NASDAQ Telecommunications Index, respectively. Historical stock performance is not necessarily indicative of future stock performance. (5) Values for Net Income for fiscal years 2024 and 2023 reflect the restatement of prior period financial statements. We determined Adjusted EBIT to be the most important financial performance measure used to link Company performance to Compensation Actually Paid to our PEO and Non-PEO NEOs in 2025. Adjusted EBIT is a non-GAAP measure. More information on Adjusted EBIT can be found in “Elements of 2025 Executive Compensation—Short-Term Cash Incentives—2025 Bonus Program” above. This performance measure may not have been the most important financial performance measure for prior years and we may determine a different financial performance measure to be the most important financial performance measure in future years.

  97. Pay Versus Performance

    | | 74 | 2026 Proxy Statement |

  98. Pay Versus Performance

    Relationship Between PEO and Non-PEO NEO Compensation Actually Paid and Total Shareholder Return (“TSR”) The following chart sets forth the relationship between Compensation Actually Paid to our PEO, the average of Compensation Actually Paid to our Non-PEO NEOs, the cumulative TSR of the Company over the five most recently completed fiscal years, and the NASDAQ Telecommunications Index TSR over the same period.

  99. Pay Versus Performance

    | | 75 | 2026 Proxy Statement |

  100. Pay Versus Performance

    Relationship Between PEO and Non-PEO NEO Compensation Actually Paid and Net Income The following chart sets forth the relationship between Compensation Actually Paid to our PEO, the average of Compensation Actually Paid to our Non-PEO NEOs, and our net income during the five most recently completed fiscal years.

  101. Pay Versus Performance

    | | 76 | 2026 Proxy Statement |

  102. Pay Versus Performance

    Description of Relationship Between PEO and Non-PEO NEO Compensation Actually Paid and Adjusted EBIT The following chart sets forth the relationship between Compensation Actually Paid to our PEO, the average of Compensation Actually Paid to our Non-PEO NEOs, and Adjusted EBIT during the five most recently completed fiscal years. Tabular List of Most Important Financial Performance Measures The following table presents the financial performance measures that the Company considers to have been the most important in linking Compensation Actually Paid to our PEO and other NEOs for 2025 to Company performance. The measures in this table are not ranked.

  103. Pay Versus Performance

    | Adjusted EBIT | | Gross Margin | | Relative TSR |

  104. Pay Versus Performance

    | | 77 | 2026 Proxy Statement |

  105. Pay Ratio

    Pay Ratio As required by SEC rules, we are providing the following information about the relationship of the annual total compensation of our employees and the annual total compensation of Mr. Stanton, our CEO. For 2025, our last completed fiscal year: the median of the annual total compensation of all employees of our Company (other than our CEO) was $90,692; and • the total compensation of our CEO in 2025, as reported in the “Total” column for 2025 of the Summary Compensation Table on page 52, was $7,683,726. Based on this information, for 2025, the ratio of the annual total compensation of our CEO to the median of the annual total compensation of all employees was approximately 85 to 1. Below is a description of the methodology and the material assumptions, adjustments and estimates that we used to identify the median of the annual total compensation of all our employees, as well as to determine the annual total compensation of the median employee. We believe that this information is useful to put into context the ratio comparing the annual total compensation of the median employee in our Company with the annual total compensation of our CEO. We determined that, as of December 31, 2025, our employee and service provider population, full and part time, consisted of approximately 3,270 individuals working at the Company and our consolidated subsidiaries. Given our global business, our workforce is distributed among a number of countries and regions. Of those, approximately 35% of these employees are located in the United States. We measured compensation using the 12-month period ended December 31, 2025. Our compensation programs vary from region to region and, among our various consolidated subsidiaries in each region, from country to country. Our employees are compensated on either a salaried basis or an hourly basis. In addition, some employees receive equity incentive awards, sales incentives and/or bonuses. We included salary or hourly wages, as applicable, as well as any equity incentive awards granted, and bonuses and sales incentives earned for 2025 in our measurement to determine the median of the annual total compensation of all our employees. Our workforce includes a number of part-time employees and service provider/contractor employees. In making our determination of the median employee, we did not annualize the compensation of part-time employees, or employees who were hired in 2025 but did not work for us or our consolidated subsidiaries for the entire fiscal year. We also did not make any cost-of-living adjustments in identifying the median employee. For purposes of this disclosure, we applied foreign currency to U.S. dollar exchange rates using the rate of exchange of each applicable currency as of December 31, 2025. Using this methodology, we determined that the median employee was a full-time, salaried employee located in the United States. With respect to the annual total compensation of the median employee, we identified and calculated the elements of such employee’s compensation for 2025 in accordance with the requirements of Item 402(c)(2)(x) of Regulation S-K and added an estimated amount for non-discriminatory health and welfare benefits, resulting in annual total compensation of $90,692. With respect to the annual total compensation of our CEO, we used the amount reported in the “Total” column for 2025 of the Summary Compensation Table appearing on page 52 and added an estimate for non-discriminatory health and welfare benefits. Given the different methodologies that various public companies use to determine an estimate of their pay ratio, the estimated ratio reported above should not be used as a basis for comparison between companies.

  106. Pay Ratio

    | | 78 | 2026 Proxy Statement |

  107. 2025 Director Compensation

    2025 Director Compensation The table below sets forth information regarding compensation paid to our non-employee directors for 2025.

  108. 2025 Director Compensation

    | Name (1) | Fees Earned or Paid in Cash ($) | Stock Awards(2) ($) | All Other Compensation ($) | Total ($) | | H. Fenwick Huss | 145,000 | 120,000 | — | 265,000 | | Gregory McCray | 90,000 | 120,000 | — | 210,000 | | Balan Nair | 90,000 | 120,000 | — | 210,000 | | Jacqueline H. Rice | 105,000 | 120,000 | — | 225,000 | | Nikos Theodosopoulos | 110,000 | 120,000 | — | 230,000 | | Kathryn A. Walker | 105,000 | 120,000 | — | 225,000 |

  109. 2025 Director Compensation

    (1) At all times during 2025, Mr. Stanton was an employee of the Company and was not compensated separately for his service on the Company’s Board. The compensation received by Mr. Stanton as an employee of the Company is shown in the Summary Compensation Table on page 52. (2) These amounts represent the aggregate grant date fair value of 13,809 shares of time-based restricted stock granted to each of the Company’s non-employee directors on December 31, 2025. The grant date fair value is computed in accordance with the Stock Compensation Topic of the FASB ASC. Each of Dr. Huss, Messrs. McCray, Nair, and Theodosopoulos, and Mses. Rice and Walker held 13,809 shares of unvested time-based restricted stock following the grant on December 31, 2025. In 2025, each of our non-employee directors received an annual cash retainer of $90,000 for service as a director, payable quarterly in advance. The Lead Director received an additional $30,000, the chairperson of the Audit Committee received an additional $25,000, the chairperson of the Compensation Committee received an additional $20,000, and the chairperson of each of the Nominating and Corporate Governance Committee and the Sustainability Committee received an additional $15,000. Such amounts are pro-rated based on the actual length of service in these positions during 2025. Directors who are employees of the Company receive no directors’ fees. All directors are reimbursed for their reasonable expenses in connection with the performance of their duties. Our non-employee directors were entitled to participate in the 2024 Directors Plan, which our stockholders approved at the 2024 Annual Meeting of Stockholders. Upon initially joining the Board, a new director will receive an initial award equal to 50% of the value of the annual equity grant made in the calendar year prior to the calendar year in which the new director joins the Board, or a lesser amount as determined in the discretion of our Board. The initial grant will be in addition to any annual grant. Grants under the 2024 Directors Plan are in the form of restricted stock unless our Board (upon recommendation from the Compensation Committee) determines to grant awards in the form of RSUs or nonqualified stock options. Awards granted under the 2024 Directors Plan (whether in the form of restricted stock, RSUs or nonqualified stock options) vest in full on the first anniversary of the grant date, unless the vesting schedule is varied by the Compensation Committee in the director’s award agreement. Any cash dividends paid on the Company’s common stock during the restricted period are credited to the director’s account and paid in additional shares at the time of vesting. Unvested shares of restricted stock vest immediately upon a change of control of the Company or if the director’s service is terminated due to death or disability. In the event of a director’s “separation from service,” such director’s rights with regard to all unvested shares of restricted stock cease immediately. The Compensation Committee may in its discretion accelerate the vesting of the unvested restricted stock or permit continued vesting on the vesting schedule set forth in the award agreement.

  110. 2025 Director Compensation

    | | 79 | 2026 Proxy Statement |