Amendment to Employment Agreement and PSU Awards for Executive Officers

ADTRAN Holdings, Inc. has amended the employment agreement for its President, CEO, and Chairman, Thomas R. Stanton. The amendment, effective April 6, 2026, eliminates the annual PSU award tied to relative total shareholder return and modifies the performance objective for long-term financial plan PSU awards to include adjustments based on relative total shareholder return. The anticipated value of RSUs and the target number of long-term financial plan PSUs for the CEO have also been adjusted. Additionally, on April 1, 2026, the Compensation Committee approved long-term financial plan PSU awards for the CEO, Chief Revenue Officer James D. Wilson, and Senior Vice President of Finance and CFO Timothy Santo. These awards are based on Adjusted EBIT performance from January 1, 2026, to December 31, 2028, with adjustments for relative total shareholder return. The Compensation Committee will not grant annual PSU awards tied to relative total shareholder return to named executive officers going forward. Specific details regarding the number of shares and performance metrics are outlined in the filing exhibits.