ADTRAN Holdings, Inc. Leadership

Dr. H. Fenwick Huss has served on the ADTRAN Board since 2002 and chairs the Audit Committee. He retired in December 2022 from Baruch College, where he was the Willem Kooyker Dean of the Zicklin School of Business, and previously served as Dean of the J. Mack Robinson College of Business at Georgia State University, bringing extensive expertise in financial accounting and corporate finance from academia.

Gregory McCray has served on the ADTRAN Board since 2017 and is an experienced executive with more than 30 years in the communications technology industry. Since August 2024 he has been CEO of PBE Axell, and he has previously led companies including FDH Infrastructure Services, Google Fiber, Aero Communications, and Antenova.

Jacqueline H. (Jackie) Rice has served on the ADTRAN Board since 2016 and chairs the Nominating and Corporate Governance Committee. Since May 2025 she has served as Chief Legal Officer and Corporate Secretary of MillerKnoll, Inc., and she previously held senior legal, risk, and compliance roles at Target Corporation and General Motors.

Nikos Theodosopoulos has served on the ADTRAN Board since 2022 and chairs the Compensation Committee, having previously chaired the supervisory board of Adtran Networks from 2015 to 2022. He runs advisory firm NT Advisors LLC, serves on the board of Hercules Capital, and was previously a Managing Director and Global Technology Strategist in equity research at UBS.

Kathryn A. Walker has served on the ADTRAN Board since 2014 and chairs the Sustainability Committee, bringing more than 30 years of communications-industry experience. Since 2009 she has been a managing director at OpenAir Equity Partners, and she previously held senior roles at subsidiaries of Sprint Corporation, culminating as Chief Information and Chief Network Officer at Sprint Nextel.

Balan Nair has served on the ADTRAN Board since 2007 and, per the 2026 proxy statement, will not stand for re-election at the annual meeting. He has served as President and Chief Executive Officer of Liberty Latin America Ltd. since 2018 and previously was Executive Vice President and Chief Technology and Innovation Officer of Liberty Global.

Anne DelSanto was elected to the ADTRAN Holdings Board effective July 1, 2026, filling a newly created seat when the Board expanded from six to seven directors. She was appointed to the Compensation Committee, and the Board determined that she qualifies as an independent director under Nasdaq listing standards.

Thomas Stanton was named ADTRAN's Chief Executive Officer in September 2005 and Chairman of the Board in 2007, and since 2023 has also served as CEO and a management board member of majority-owned subsidiary Adtran Networks SE (formerly ADVA Optical Networking SE). He joined ADTRAN in 1995 as Vice President of Marketing for the Carrier Networks division and held a range of senior positions, including Senior Vice President and General Manager of that division, before earlier roles at Transcrypt International and E. F. Johnson Company.

Timothy Santo was appointed ADTRAN's Senior Vice President of Finance and Chief Financial Officer effective March 10, 2025, also serving as Principal Accounting Officer and Treasurer, and as CFO and a management board member of Adtran Networks. Before joining ADTRAN he served in a variety of finance roles at Conn's, Inc., including Executive Vice President and Chief Financial Officer, and previously was Senior Vice President and Global Controller of PRA Group, Inc.

Christoph Glingener has served as ADTRAN Holdings' Chief Technology Officer since 2023 and is the CTO and a management board member of Adtran Networks SE (formerly ADVA Optical Networking SE). He served as Chief Executive Officer of Adtran Networks from 2022 to 2023 and as its Chief Technology Officer from 2007 to 2022.

James D. Wilson, Jr. has served as ADTRAN's Chief Revenue Officer since 2019. He joined ADTRAN in 2006, previously serving as Senior Vice President of Technology and Strategy from 2015 to 2019 and as Senior Vice President and General Manager of the Carrier Networks division from 2006 to 2015.

Ulrich Dopfer served as ADTRAN's Senior Vice President of Finance and Chief Financial Officer until March 10, 2025, when he transitioned to the role of Vice President, Finance & Administration Planning. He continues to serve as a management board member of majority-owned subsidiary Adtran Networks SE and remained a named executive officer for fiscal 2025.