Exhibit 10.1

[Signature Page follows]

Exhibit 1 / Anlage 1

Officer’s Remuneration

The Officer’s annual Base Salary will be increased to EUR 400.000 p.a., and this increased Base Salary shall be paid pro rata starting on October 1, 2025 until December 31, 2026 (“Base Salary”) i.e. EUR 100,000 for the period from October 1, 2025 to December 31, 2025 and EUR 400,000 for the calendar year 2026.

The Annual Target Incentive Cash Bonus (“VICC”) in the amount of 60% of the Base Salary will be pro-ratably calculated for the calendar year 2025 based on an annual Base Salary of EUR 337.000 for the period January 1, 2025 until September 30, 2025 and based on an annual Base Salary of EUR 400.000 for the period October 1, 2025 until December 31, 2025.

For 2025, the VICC is calculated based on the achievement of two Company Performance Measurements (“CPM”): 1) Total Company Revenue of Adtran and 2) Total Company Adjusted Earnings before Interest and Taxes ("Adjusted EBIT") of Adtran, each CPM comes with a minimum threshold for payout, a "target", and a maximum, with linear increase for the payout percentage that will be interpolated up to the Maximum based on actual achievement of each CPM and subject to Adtran’s specific terms of the VICC. The actual payout may be between 0% to 200% of target based on achievement.

For 2026, should ADTRAN Holdings, Inc. Compensation Committee approve and recommend a VICC (“VICC 2026”) which is covered by the Company’s Remuneration System, this VICC 2026 will be in the amount of 60% of the Base Salary of EUR 400.000 for the period January 1, 2026 until December 31, 2026 and will be calculated based on the achievements of the CPMs approved at that time. Each approved CPM will have a minimum threshold for payout, a "target", and a maximum, with linear increase for the payout percentage that will be interpolated up to the Maximum based on actual achievement of each CPM and subject to Adtran’s specific terms of the VICC 2026. The actual payout may be between 0% to 200% of target based on achievement.

The actual payout of the VICC will not be prevented or reduced by any language in the Additional Documents or in Section 9 Miscellaneous below, but only by the Company’s achievement of the CPMs and the minimum thresholds and, in case of only a partial provision of services during the term of the Employment Agreement’s service period, a respective pro-rata portion. In particular, the actual payout of the VICC will not be prevented or impacted by the fact that the Officer is no longer an officer or employee of the Company at the time of the calculation, payout, or has not renewed

the Employment Agreement, unless the Officer’s Employment Agreement is terminated by the Company for cause or in case of a withholding or recovery of remuneration (malus/clawback) according to Section 5 of the Remuneration System.

Given the annual grant of time-based restricted stock units (“RSUs”) for 2025 was already awarded, the 2026 annual grant of RSUs is a target amount of 40% of Base Salary of EUR 400.000 that amounts to EUR 160.000 (“Annual RSU Grant”) with 25% vesting on each of the first four anniversaries of the grant date settled through delivery of one Adtran share of common stock for each vested RSU conditioned upon an existing employment relationship on the applicable vesting date. The grants are subject to Adtran’s specific terms of the Annual RSU Grant, and an exercise profit limitation (Cap) in case of a value increase to 300% between disbursement and conversion, taking into consideration all RSUs allocated within the grant for Officer of EUR 480.000.

Given the annual grant of market-based performance stock units (“PSU”) for 2025 was already awarded, the 2026 annual grant of PSUs is a target amount of 40% of Base Salary of EUR 400.000 that amounts to EUR 160.000 with payout based on Adtran’s relative Total Shareholder Return (“TSR”) performance compared to the Nasdaq Telecommunications Index over a 3-year performance period ("Annual PSU Grant”). Depending on Adtran’s relative TSR over the performance period, Officer may earn from 0% of the target number of market-based PSUs if the relative TSR performance is not at least equal to the 30th percentile of the peer group, and 150% of the target number of market-based PSUs if the relative TSR performance of Adtran equals or exceeds the 80th percentile of the peer group, based on the sliding scale where approximately 4.0% 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 grant. However, there is a 100% payout cap when Adtran’s TSR out-performs the NASDAQ Telecommunications Index, but Adtran’s TSR is negative. The recipients of the market-based PSUs receive dividend credits, provided dividends are declared and paid to shareholders, in cash based on the shares of common stock underlying the market-based PSUs. The grants are subject to an exercise limitation in case of achievement of the 150% maximum target and a share value increase to 200% between disbursement and conversion, taking into consideration all market-based PSUs allocated within the grant (Cap) for Officer of EUR 480.000.

Officer agrees and acknowledges that market based PSUs under a 3-year performance-based PSU plan are eligible to be earned only after Officer is with the Company at the end of a 3-year

performance period and if the relative TSR is achieved, and no pro-rata achievement or pro-rata earnings will apply in the event Officer’s Employment Agreement has ended or has not been renewed before the end of the 3-year performance period.

On May 24, 2023, performance-based performance stock units (“performance-based PSUs”) in a target amount of EUR 934.579 (USD 1,000,000) or 60,205 shares were granted to Officer by Adtran (Employee Grant Number 5220). Pursuant to the terms of the award, shares are eligible to be earned at the end of the 3-year performance period ending on December 31, 2025 based on a target achievement of Adtran’s Adjusted EBIT of USD 252 million during such performance period. The recipients of the performance-based PSUs also receive dividend credits, provided dividends are declared and paid to shareholders, in cash based on the shares of common stock underlying the performance-based PSUs. The grants are subject to an exercise limitation in case of a share value increase to 200% of the originally allocated performance-based PSUs between disbursement and conversion, taking into consideration all performance-based PSUs originally allocated (Cap) for Officer’s grant of USD 2,000,000.

Should Adtran Holdings, Inc. Compensation Committee recommend to grant new 3-Year Performance-Based PSUs for a performance period starting January 1, 2026 or thereafter in an amount and according to terms covered by Company’s remuneration system then the Officer also participates in such new 3-year performance-based PSU plan substituting the current one.

Officer agrees and acknowledges that performance-based PSUs under a 3-year performance-based PSU plan are eligible to be earned only after Officer is with the Company at the end of a 3-year performance period and if the goals under the 3-Year Performance-Based PSU plan are actually achieved at the time of achievement, and no pro-rata achievement or pro-rata earnings will apply in the event Officer’s Employment Agreement has ended or has not been renewed before the end of the 3-year performance period.

The Jährliche Maximalvergütung/Annual maximum remuneration cap for the Officer is EUR 2.800.000 and will be calculated according to Section 2 of the Company’s Remuneration System. Accordingly, the maximum remuneration is comprised of the basic remuneration and the fringe benefits, the variable (i.e. performance-related) remuneration components in case of maximum target achievement, and taking into consideration any applicable caps. For the company-related PSUs, the achievable maximum amounts are distributed evenly over the individual years of the term. As a precautionary measure, any remuneration that Adtran pays the Officer with regard to his service on the Management Board at the Company (in particular RSUs as well as market- and

company-related PSUs) will also be considered. If members of the Board of Directors or other senior managers of the Adtran Group also hold a seat on the Management Board at the Company at the same time, any amounts that are not paid by the Company or its dependent companies and that are not paid specifically for the service on the Management Board at the Company will not be taken into consideration.

The term "Adjusted EBIT" is Adtran’s earnings before interest and taxes shown in the audited financial statements of Adtran, adjusted by restructuring costs, acquisition-related costs, amortizations of intangible assets, costs for share-based compensation, non-cash changes in the value of investments within the framework of the Deferred Compensation Plan, and other exceptions established in the individual case. However, according to the VICC, other key figures can also be used as performance criteria.

The remuneration agreed in this Amendment includes any remuneration increase for the calendar years 2025 that the Compensation Committee of Adtran Holdings, Inc. has recommended, including, but not limited to an increase of the Base Salary starting in April 1, 2025 for the executive officers and/or the management team of Adtran Holdings, Inc. Should the Compensation Committee of Adtran Holdings, Inc. recommend or resolve an increase of the Base Salary for the executive officers and/or the management team of Adtran Holdings, Inc. for the calendar year 2026 (“2026 Increase”), then the Officer is not eligible to claim such a 2026 Increase.

The variable remuneration described in this document is subject to Adtran’s calculations, descriptions, terms of the applicable plans and programs of Adtran, including, without limitation, the ADTRAN HOLDINGS, INC. AMENDED AND RESTATED VARIABLE INCENTIVE COMPENSATION PLAN (“VICC”), the ADTRAN HOLDINGS, INC. AMENDED AND RESTATED CLAWBACK POLICY, the ADTRAN HOLDINGS, INC. POLICY FOR THE RECOVERY OF ERRONEOUSLY AWARDED INCENTIVE BASED COMPENSATION (“Clawback Policy”), the ADTRAN HOLDINGS, INC. 2024 EMPLOYEE STOCK INCENTIVE PLAN, and subject to Officers’ express approval that will not be unreasonably withheld any other current or future plan and its respective amendments where applicable (collectively “Additional Documents”), provided that the terms and conditions expressly agreed in this Amendment shall prevail in the event of any conflict or inconsistency with the Additional Documents, unless the Officer’s Employment Agreement is terminated by the Company for cause or in case of a withholding or recovery of remuneration (malus/clawback) according to Section 5 of the Remuneration System.