NOTICE OF 20162024 ANNUAL MEETING

AND

PROXY STATEMENT

		Corporate Office		U.S. Mail		Toll-Free: 1 800 9Adtran
		901 Explorer Blvd.		P.O. Box 140000		Telephone: 256 963 8000
		Huntsville, AL 35806		Huntsville, AL 35814-4000		http://www.adtran.com

April 4, 2016March 27, 2024

Dear Stockholder:

You are cordially invited to attend the 20162024 Annual Meeting of Stockholders of ADTRAN Holdings, Inc. to be held at ADTRAN’s headquarters at 901 Explorer Boulevard, Huntsville, Alabama, on Wednesday, May 11, 2016,8, 2024, at 10:30 a.m., local time. The meetingCentral Time. We are pleased to announce that this year’s Annual Meeting will be helda virtual meeting conducted by live webcast on the Internet. You will be able to attend and participate in the East Towermeeting by visiting www.virtualshareholdermeeting.com/ADTN2024 and entering the 16-digit control number included on your Notice of Internet Availability of Proxy Materials (the “Notice”) or on your proxy card if you receive the second floor.proxy materials by mail. You will not be able to attend the Annual Meeting in person.

The attached Notice of Annual Meeting of Stockholders and Proxy Statement describesdescribe the formal business to be transacted at the meeting. During the meeting, we also will report on ADTRAN’sAdtran’s operations during the past year and our plans for the future. Our directors

We have elected to take advantage of Securities and officers, as well as representatives fromExchange Commission rules that allow issuers to furnish proxy materials to their stockholders on the Internet. We believe that the rules will allow us to provide our independent registered public accounting firm, PricewaterhouseCoopers LLP, will be present to respond to appropriate questions from stockholders.stockholders with the information they need, while lowering the costs of delivery and reducing the environmental impact of the annual meeting.

Your vote, whether during the virtual meeting on May 8, 2024 or by proxy, is important. Please mark, date, sign and returnreview the instructions on each of your proxy cardvoting options described in the enclosed envelope, or vote by telephone or overaccompanying proxy materials and the Internet as directed onNotice you received in the enclosed proxy card, at your earliest convenience. This will assure that your shares will be represented and voted atmail. If you are unable to participate in the virtual meeting, even ifI urge you do not attend.

For ease of voting, stockholders are encouraged to vote using the Internet. If you would like to reduce the costs incurred by ADTRAN, Inc. in mailing proxy materials, you can consent to receive all future proxy statements, proxy cards, and annual reports electronically. To sign up for electronic delivery, please vote using the Internet and, when prompted, indicate that you agree to receive or access stockholder communications electronically in future years.as soon as possible.

Sincerely,

THOMAS R. STANTON

Chairman of the Board

ADTRAN HOLDINGS, INC.

901 EXPLORER BOULEVARD

HUNTSVILLE, ALABAMA 35806

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD WEDNESDAY, MAY 11, 20168, 2024

NOTICE HEREBY IS GIVEN that the 20162024 Annual Meeting of Stockholders (the “Annual Meeting”) of ADTRAN Holdings, Inc. (the “Company”) will be held at ADTRAN’s headquarters at 901 Explorer Boulevard, Huntsville, Alabama, on the second floor of the East Tower, on Wednesday, May 11, 2016,8, 2024, at 10:30 a.m., local time,Central Time, via live webcast. You can participate in the meeting by visiting www.virtualshareholdermeeting.com/ADTN2024 and entering the 16-digit control number included on your Notice or proxy card. If you hold your shares through an intermediary, such as a bank or broker, and do not have a control number, please contact the bank or broker. Please log in to the website by 10:15 a.m., Central Time, on the day of the meeting. There is no physical location for the Annual Meeting.

The Annual Meeting is being held for the purposes of considering and voting upon:

“RESOLVED, that the stockholders approve the overall executive compensation policies and procedures employed by the Company as well as the compensation of the named executive officers, all as described in the Compensation Discussion and Analysis and the tabular disclosure regarding named executive officer compensation in this Proxy Statement.”

The Board of Directors recommends that you vote FOR each of the eight director nominees; FOR the adoption of the ADTRAN Holdings, Inc. 2024 Employee Stock Incentive Plan; FOR the adoption of the ADTRAN Holdings, Inc. 2024 Directors Stock Plan; FOR the approval on an advisory basis of the compensation of the Company’s NEOs; and FOR the ratification of the appointment of PricewaterhouseCoopers LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2024. The Annual Meeting may be adjourned from time to time without notice other than announcement at the meeting or at adjournments thereof, and any business for which notice is hereby given may be transacted at any such adjournment.

Information relating to the above matters is set forth in the attached Proxy Statement. Stockholders of record at the close of business on March 14, 201611, 2024, are entitled to receive notice of and to vote atduring the Annual Meeting and any adjournments thereof.

Whether or not you plan to participate in the Annual Meeting, we urge you to review these materials carefully, which are available at https://materials.proxyvote.com/00486H. We also encourage you to vote by (i) following the instructions on the notice that you received from your broker, bank or other nominee if your shares are held beneficially in “street name” or (ii) one of the following means if your shares are registered directly in your name with the Company’s transfer agent:

You can submit questions in advance of the Annual Meeting by visiting www.proxyvote.com, entering your 16-digit control number, and using the “Questions for Management” feature. You can submit questions during the Annual Meeting by following the instructions on the meeting website. Management will answer pertinent questions in the “Investor Resources” section of our website at https://investors.adtran.com. The questions and answers will be available as soon as practicable after the Annual Meeting and will remain available for thirty (30) days after posting.

By Orderorder of the Board of Directors.Directors,

ROGER D. SHANNON

ULRICH DOPFER

Senior Vice President of Finance, Chief Financial Officer, Corporate Secretary and Treasurer

Huntsville, Alabama

April 4, 2016March 27, 2024

TABLE OF CONTENTS

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ii

PROXY STATEMENT FOR THE ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD WEDNESDAY, MAY 8, 2024

This Proxy Statement, along with the accompanying Notice of Annual Meeting of Stockholders, contains information about the 2024 Annual Meeting of Stockholders (the “Annual Meeting”) of ADTRAN Holdings, Inc. (the “Company”), including any adjournments or postponements of the Annual Meeting. The Annual Meeting will be held on Wednesday, May 8, 2024 at 10:30 a.m., Central Time. We are pleased to announce that this year’s Annual Meeting will be a virtual meeting conducted by live webcast on the Internet. You will be able to attend and participate in the meeting by visiting www.virtualshareholdermeeting.com/ADTN2024 and entering the 16-digit control number included on your Notice of Internet Availability of Proxy Materials (the “Notice”) or on your proxy card if you receive the proxy materials by mail. If you hold your shares through an intermediary, such as a bank or broker, and do not have a control number, please contact the bank or broker. Please log in to the website by 10:15 a.m., Central Time, on the day of the meeting. You may vote during the Annual Meeting by following the instructions available on the meeting website. There is no physical location for the Annual Meeting.

You can submit questions in advance of the Annual Meeting by visiting www.proxyvote.com, entering your 16-digit control number, and using the “Questions for Management” feature. You can submit questions during the Annual Meeting by following the instructions on the meeting website. Management will answer pertinent questions in the “Investor Resources” section of our website at https://investors.adtran.com. The questions and answers will be available as soon as practicable after the Annual Meeting and will remain available for thirty (30) days after posting.

We are providing this Proxy Statement to the stockholders of the Company in connection with the solicitation of proxies by our Board of Directors to be voted during the Annual Meeting and at any adjournments of that meeting.

On or about March 27, 2024, we began sending the Notice to all stockholders entitled to vote in advance of or during the virtual Annual Meeting. We encourage all of our stockholders to vote on the proposals presented, and we hope the information contained in this document will help you decide how you wish to vote.

Important Notice Regarding the Availability of Proxy Materials for the

Annual Meeting of Stockholders to be Heldheld on May 11, 2016:8, 2024:

This Notice, the Proxy Statement and the 20152023 Annual Report to Stockholders of ADTRAN Holdings, Inc. are available free of charge to view, print and download at https://materials.proxyvote.com/00486H.

availableAdditionally, you can find a copy of our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, including financial statements and schedules thereto, on the website of the Securities and Exchange Commission (the “SEC”) at www.proxyvote.com.

PLEASE READ THE ATTACHED PROXY STATEMENT AND THEN PROMPTLY COMPLETE, EXECUTE AND RETURN THE ENCLOSED PROXY CARD IN THE ACCOMPANYING POSTAGE-PAID ENVELOPE OR VOTE BY TELEPHONE OR OVER THE INTERNET AS INSTRUCTED ON THE ENCLOSED PROXY CARD.

www.sec.gov, or in the “SEC Filings” section of our website at https://investors.adtran.com. You may also obtain a printed copy of our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, including financial statements and schedules thereto, free of charge, from us by sending a written request to: ADTRAN INC.

901 EXPLORER BOULEVARD

HUNTSVILLE, ALABAMA 35806

PROXY STATEMENT

FOR THE ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD MAY 11, 2016

We are providing this Proxy Statement to the stockholders of ADTRAN,Holdings, Inc. in connection with the solicitation of proxies by our Board of Directors to be voted at the 2016 Annual Meeting of Stockholders and at any adjournments of that meeting. The Annual Meeting will be held at ADTRAN’s headquarters,, Attn: Corporate Secretary, 901 Explorer Boulevard, Huntsville, Alabama 35806. Exhibits will be provided upon written request.

GENERAL INFORMATION ABOUT THE ANNUAL MEETING

Why is the Company soliciting my proxy?

The Board of Directors of the Company (the “Board”) is soliciting your proxy to vote at the 2024 Annual Meeting of Stockholders to be held on Wednesday, May 11, 2016,8, 2024 at 10:30 a.m., local time. TheCentral Time, via live webcast and any adjournments of the meeting, which we refer to as the “virtual Annual Meeting” or the “Annual Meeting.” This Proxy Statement along with the accompanying Notice of Annual Meeting of Stockholders summarizes the purposes of the meeting and the information you need to know to vote during the Annual Meeting.

How can I participate in the virtual Annual Meeting?

You will be heldable to attend and participate in the East TowerAnnual Meeting by visiting www.virtualshareholdermeeting.com/ADTN2024 and entering the 16-digit control number included on your Notice or proxy card. If you hold your shares through an intermediary, such as a bank or broker, and do not have a control number, please contact the bank or broker. Please log in to the website by 10:15 a.m., Central Time, on the second floor. When usedday of the meeting. You may vote during the Annual Meeting by following the instructions available on the meeting website.

You can submit questions in this Proxy Statement,advance of the terms “we,” “us,” “our”Annual Meeting by visiting www.proxyvote.com, entering your 16-digit control number, and “ADTRAN” referusing the “Questions for Management” feature. You can submit questions during the Annual Meeting by following the instructions on the meeting website. Management will answer pertinent questions in the “Investor Resources” section of our website at https://investors.adtran.com. The questions and answers will be available as soon as practicable after the Annual Meeting and will remain available for thirty (30) days after posting.

Why did I receive a one-page notice in the mail regarding the Internet availability of proxy materials instead of a full set of proxy materials?

In accordance with rules and regulations adopted by the SEC, instead of mailing a printed copy of our proxy materials to ADTRAN, Inc.

The approximate date on whicheach stockholder of record, we are furnishing proxy materials, including this Proxy Statement and form of proxy card are first being sent or given to stockholders is April 4, 2016.

This Proxy Statement, the attached Notice of Annual Meeting and our 20152023 Annual Report to Stockholders, are available at www.proxyvote.com.by providing access to such documents on the Internet. Stockholders will not receive printed copies of the proxy materials unless they request them. Instead, commencing on or about March 27, 2024, a Notice was sent to our stockholders which instructs you on how to access and review the proxy materials on the Internet. The Notice also instructs you on how to submit your proxy via the Internet or by telephone. If you would like to receive a paper or email copy of our proxy materials, please follow the instructions for requesting such materials in the Notice.

VOTINGWhy am I receiving these materials?

General

The securities that can be voted atOur Board is providing these proxy materials to you on the Internet or, upon your request, will deliver printed versions of these materials to you by mail, in connection with the Annual Meeting, consistwhich will take place on May 8, 2024. Stockholders are invited to participate in the virtual Annual Meeting and are requested to vote on the proposals described in this Proxy Statement.

What is included in these materials?

These proxy materials include:

If you request printed versions of these materials by mail, these materials will also include the proxy card for the Annual Meeting.

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What proposals will be voted on during the Annual Meeting?

You will be voting on the matters listed below (with the Board’s recommendation on each matter):

What shares owned by me can be voted?

All shares owned by you as of the close of business on March 11, 2024 (the “Record Date”) may be voted. You may cast one vote per share of common stock that you held on the Record Date. These include shares that are: (1) held directly in your name as the stockholder of record, and (2) held for you as the beneficial owner through a stock broker, bank or other nominee. At the close of business on the Record Date, there were 79,115,792 shares of our common stock $0.01 par value per share, with each share entitling its owneroutstanding. Each stockholder is entitled to one vote on each matter submitted to the stockholders. The record date for determining the holders of common stock who are entitled to receive notice of and to vote at the Annual Meeting is March 14, 2016. On the record date, 48,989,616 shares of common stock were outstanding and eligible to be voted at the Annual Meeting.

Quorum and Vote Required

The presence, in person or by proxy for each share of common stock held on all matters properly to come before the Annual Meeting.

What is the difference between holding shares as a stockholder of record and as a beneficial owner?

Most of the Company’s stockholders hold their shares through a stock broker, bank or other nominee rather than directly in their own name. As summarized below, there are some differences between shares held of record and those owned beneficially through a nominee.

Stockholder of Record

If your shares are registered directly in your name with the Company’s transfer agent, American Stock Transfer & Trust Company, LLC, you are considered the stockholder of record with respect to those shares, and the Notice is being sent directly to you. As the stockholder of record, you have the right to grant your voting proxy directly to the persons named as proxy holders, Thomas R. Stanton, the Company’s Chief Executive Officer and Chairman of the Board, and Ulrich Dopfer, the Company’s Senior Vice President of Finance, Chief Financial Officer, Corporate Secretary and Treasurer, or to vote prior to or during the virtual Annual Meeting. If you request printed copies of the proxy materials, the Company will provide a proxy card for you to use. You may also vote by Internet or by telephone, as described below under the heading “How can I vote my shares without participating in the Annual Meeting in real time?”

Beneficial Owner

If your shares are held in a stock brokerage account or by a bank or other nominee, you are considered the beneficial owner of shares held in “street name,” and a notice is being sent to you by your broker or nominee who is considered the stockholder of record with respect to those shares. As the beneficial owner, you are invited to participate in the virtual Annual Meeting. You also have the right to direct your broker on how to vote these shares. The notice that you receive from your broker or nominee should include instructions for you to direct your broker or nominee how to vote your shares. You may also vote prior to the Annual Meeting by Internet or by telephone, as described below under “How can I vote my shares without participating in the Annual Meeting in real time?” However, shares held in “street name” may be voted during the Annual Meeting by you only if you obtain a signed proxy from the record holder (broker, bank or other nominee) giving you the right to vote the shares.

2

How can I vote my shares during the virtual Annual Meeting?

Shares held directly in your name as the stockholder of record or shares held beneficially in “street name” may be voted during the virtual Annual Meeting. If you choose to vote your shares during the virtual Annual Meeting and you are the stockholder of record, you will need the control number included on your Notice or proxy card. If you hold your shares in “street name” and do not have a control number, please contact the bank or broker.

How can I vote my shares without participating in the Annual Meeting in real time?

Whether you hold your shares directly as the stockholder of record or beneficially in “street name,” you may direct your vote by proxy without participating in the virtual Annual Meeting in real time. If you are the stockholder of record, you can vote by proxy by one of the following means:

If you hold your shares beneficially in “street name,” please follow the instructions provided in the notice from your broker, or, if you request printed copies of proxy materials, on the proxy card or voting instruction form. We urge you to review the proxy materials carefully before you vote. These materials are available at https://materials.proxyvote.com/00486H.

Can I revoke my proxy or change my vote?

You may revoke your proxy or change your voting instructions prior to the vote during the virtual Annual Meeting. You may enter a new vote by using the Internet or the telephone or by mailing a new proxy card or new voting instruction form bearing a later date (which will automatically revoke your earlier voting instructions), which new vote must be received by 11:59 p.m., Central Time, on May 7, 2024. You may also enter a new vote by participating in and voting during the virtual Annual Meeting. Your participation in the Annual Meeting will not cause your previously granted proxy to be revoked unless you specifically so request.

3

What is the voting requirement to approve each of the proposals?

What does it mean if I receive more than one Notice, proxy card or voting instruction form?

It means your shares are registered differently or are held in more than one account. For each Notice you receive, please submit your vote for each control number you have been assigned. If you request and receive paper copies of proxy materials, please provide voting instructions for all proxy cards and voting instruction forms you receive.

Where can I find the voting results of the Annual Meeting?

We will announce preliminary voting results during the Annual Meeting and publish preliminary results, or final results if available, in a Current Report on Form 8-K within four business days of the Annual Meeting. If final results are unavailable at the time we file the Form 8-K, then we will file an amended report on Form 8-K to disclose the final voting results within four business days after the final voting results are known.

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What happens if additional proposals are presented during the Annual Meeting?

Other than the five proposals described in this Proxy Statement, we do not expect any matters to be presented for a vote during the Annual Meeting. If you grant a proxy, the persons named as proxy holders, Thomas R. Stanton, the Company’s Chief Executive Officer and Chairman of the Board, and Ulrich Dopfer, the Company’s Senior Vice President of Finance, Chief Financial Officer, Corporate Secretary and Treasurer, will have the discretion to vote your shares on any additional matters properly presented for a vote during the Annual Meeting. If for any unforeseen reason, any one or more of the Company’s nominees for director is not available as a candidate for director, the persons named as proxy holders will vote your proxy for such other candidate or candidates as may be nominated by the Board of Directors.

What is the quorum requirement for the Annual Meeting?

The quorum requirement for holding the Annual Meeting and transacting business is a majority of the outstanding shares of our common stock is necessaryentitled to constitute a quorumvote or act at the meeting. The shares may be present by participating in the Annual Meeting or represented by proxy at the Annual Meeting. In countingBoth abstentions and broker non-votes are counted as present for the votes to determine whetherpurpose of determining the presence of a quorum exists at the Annual Meeting, we will use the proposal receiving the greatest number of all votes “for” or “against” and abstentions, including instructions to withhold authority to vote.

In voting with regard to Proposal 1, the election of directors, stockholders may vote in favor of all nominees, withhold their votes as to all nominees or withhold their votes as to specific nominees. The vote required to approve Proposal 1 is governed by the Bylaws of the Company and is a majority of the votes cast by the holders of shares represented and entitled to vote at the Annual Meeting, providedquorum. If a quorum is present. As a result, abstentions will be considered in determining whether a quorumnot present or if we decide that more time is present and the number of votes required to obtain the necessary majority vote for the nominees and, therefore, will havesolicitation of proxies, we may adjourn the same legal effect as voting againstAnnual Meeting. We may do this with or without a stockholder vote. Alternatively, if the proposal.

In voting with regard to Proposal 2, an advisorystockholders vote to approve the Company’s executive compensation, stockholders may vote in favor of the proposal or against the proposal or may abstain from voting. As the vote is advisory only and not binding there is no required vote. In determining the results of the vote, however, abstentions will have the same legal effect as voting against the proposal.

In voting with regard to Proposal 3, the ratification of the appointment of the independent registered public accounting firm, stockholders may vote in favor of the proposal or against the proposal or may abstain from voting. The vote required to approve of Proposal 3 is governed by Delaware law and is the affirmative vote of the holders of a majority of the shares represented and entitled to vote on the proposals at the Annual Meeting, provided a quorum is present. As a result, abstentions will be considered in determining whether a quorum is present and the number of votes required to obtain the necessary majority vote for each proposal and, therefore, will have the same legal effect as voting against the proposal.

1

Under the rules of the national stock exchanges that govern most domestic stock brokerage firms, member firms that hold shares in street name for beneficial owners may, to the extent that those beneficial owners do not furnish voting instructions with respect to any or all proposals submitted for stockholder action, vote in their discretion upon proposals that are considered “discretionary” proposals under the rules of the exchanges. These votes by brokers are considered as votes cast in determining the outcome of any discretionary proposal. We believe that Proposal 3 is discretionary. Member brokerage firms that have received no instructions from their clients as to “non-discretionary” proposals do not have discretion to vote on these proposals. If the brokerage firm returns a proxy card without voting on a non-discretionary proposal because it received no instructions, this is referred to as a “broker non-vote” on the proposal. “Broker non-votes” are considered in determining whether a quorum exists at the Annual Meeting, but “broker non-votes” are not considered as votes cast in determining the outcome of any proposal. We believe Proposals 1 and 2 are non-discretionary.

As of March 14, 2016, the record date for the Annual Meeting, our directors and executive officers beneficially owned or controlled approximately 1,483,389 shares of our common stock, constituting approximately 2.96% of the outstanding common stock. We believe that these holders will vote all of their shares of common stock in favor of each of the proposals.

Proxies

You should specify your choices with regard to each of the proposals (1) by telephone as directed on the enclosed proxy card, (2) over the Internet as directed on the enclosed proxy card, or (3) on the enclosed proxy card by signing, dating and returning it in the accompanying postage paid envelope. All properly executed proxy cards delivered by stockholders to ADTRAN in time to be voted at the Annual Meeting and not revoked will be voted atadjourn the Annual Meeting in accordance with the directions noted onCompany’s Bylaws, the proxy card.Innamed proxies will vote all shares of common stock for which they have voting authority in favor of adjournment.

Who will bear the absencecost of such instructions,soliciting proxies for the shares represented by a signed and dated proxy cardAnnual Meeting?

The Company will be voted “FOR”pay the electionentire cost of all director nominees, “FOR” approval of a shareholder advisory vote on executive compensation and “FOR” the ratification of the appointment of the independent registered public accounting firm.If any other matters properly come beforesoliciting proxies for the Annual Meeting, including the persons named as proxies will vote upon those matters according to their judgment.

Any stockholder delivering adistribution of proxy has the power to revoke it at any time before it is voted by:

Please note, however, that under the rules of the national stock exchanges, any beneficial owner of our common stock whose shares are held in street name by a member brokerage firm may revoke his proxy and vote his shares in person at the Annual Meeting only in accordance with applicable rules and procedures of the exchanges, as employed by the beneficial owner’s brokerage firm.

In addition to soliciting proxies through the mail, we may solicit proxies through our directors, officers and employees in person and by telephone or facsimile.materials. We have hired Georgeson Inc. to assist in the solicitation of proxies from stockholders at a fee of approximately $9,000 plus reasonable out-of-pocket expenses. We will pay allrequest brokers or nominees to forward this Proxy Statement to their customers and principals and will reimburse them for expenses incurred in connection with the solicitation of proxies. Weso incurred. If deemed necessary, we may also request that brokerage firms, nominees, custodiansuse our officers and fiduciaries forward proxy materialsregular employees, without additional compensation, to the beneficial owners of shares held of recordsolicit proxies personally or by them. We will also reimburse such brokerage firms and other nominees for their reasonable expenses in forwarding proxy materials to beneficial owners of our common stock.

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SHARESECURITY OWNERSHIP OF PRINCIPAL STOCKHOLDERSCERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth information regarding the beneficial ownership of our common stock as of March 14, 2016,11, 2024, by (1) each of our directors, (2) each of our executive officers named in the Summary Compensation Table in this Proxy Statement and (3) all of our current directors and executive officers as a group, based in each case on information furnished to us by these persons. We believe that each of the named individuals and each director and executive officer included in the group has sole voting and investment power with regard to the shares shown except as otherwise noted.

6

3

7

The following table sets forth information regarding the beneficial ownership of our common stock as of the date indicated for each person, other than the officers or directors of ADTRAN,Adtran, known to us to be the beneficial owner of more than 5% of our outstanding common stock.

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PROPOSAL 1 –

ELECTION OF DIRECTORS

NomineesOur Board of Directors

TheOur Board of Directors currently consists of seveneight members. Each of Thomas R. Stanton, H. Fenwick Huss, William L. Marks, Balan Nair, Roy J. Nichols and Kathryn A. Walker were elected at the 2015 Annual Meeting. Anthony J. Melone was appointed as a director by the Board on February 8, 2016, to fill a previously existing vacancy.

The Board of Directors has nominated Thomas R. Stanton, H. Fenwick Huss, William L. Marks, AnthonyGregory J. Melone,McCray, Balan Nair, Roy J. NicholsBrian Protiva, Jacqueline H. Rice, Nikos Theodosopoulos and Kathryn A. Walker for election as directors at the 20162024 Annual Meeting. Each of these individuals currently serves as a director.

In July 2022, the Company completed a business combination pursuant to which ADTRAN, Inc. and Adtran Networks SE, a company organized and existing under the laws of Germany (“Adtran Networks,” formerly ADVA Optical Networking SE), became subsidiaries of the Company (the “Business Combination”). Each of Messrs. Stanton, Huss, McCray and Nair and Mses. Rice and Walker, the directors of ADTRAN, Inc., was elected to the Board of the Company, as the successor issuer to ADTRAN, Inc. In connection with the Business Combination, each of Brian Protiva and Nikos Theodosopoulos was elected to the Company’s Board, and Mr. Protiva was named Vice Chairman of the Board. The skills that these new directors bring to the Board are instrumental to our achievement of synergies and global strategy going forward. References in this Proxy Statement to “Adtran,” the “Company,” “we,” “our” and “us” refer to ADTRAN, Inc. prior to the Business Combination and to ADTRAN Holdings, Inc. following the Business Combination.

If elected as a director at the Annual Meeting, each of the nominees would serve a one-year term expiring at the 20172025 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.

Each Pursuant to the Company’s Director Resignation Policy, each of the director nominees has consentedis deemed to serve his term as a director if elected. If anyhave agreed to promptly tender to the Chairman of the nominees should be unavailable to serve for any reason (which is not anticipated), the Board of Directors may designatean irrevocable contingent resignation in the event that such director fails to receive a substitutesufficient number of votes for re-election (a “majority against vote”). If any director nominee or nominees (in which eventreceives a majority against vote at the persons named onAnnual Meeting, the enclosed proxy card will vote the shares represented by all valid proxies for the electionNominating and Corporate Governance Committee of the substitute nomineeBoard of Directors will recommend to the Board, and the Board will determine, whether to accept or nominees), allowreject the vacancies to remain open untilresignation tendered by such individual. Following the Board’s decision, the Company will file a suitable candidate or candidates are located, or by resolution provide for a lesser number of directors.

Our products and our success in our markets dependCurrent Report on our ability to stay abreast of and respond to developments in communications and information technologies. We have also grown profitably;Form 8-K with the SEC in order to protectdisclose the decision and, enhanceif applicable, the Board’s reasoning for rejecting the tendered resignation.

Our Bylaws provide that our growthBoard consists of a single class of directors and profitability itthat the terms of office of the directors is important for usone year from the time of their election until the next annual meeting of stockholders and until their successors are duly elected and qualified. In addition, our Bylaws provide that, in general, vacancies on our Board may be filled by a majority of directors in office, even if less than a quorum, or by a sole remaining director (and not by the stockholders). Our Bylaws provide that the exact number of directors will be fixed from time to understandtime by our Board pursuant to a resolution adopted by a majority of the financial environments which impact uswhole Board.

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 riskslaws 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 those environments as well as the toolsan effort to achieve diversity of corporate finance available to us to navigateskills and manage those risks. We also have a significant number of employees and numerous locations. In selecting directors we are concerned to have a diverse group ofexperience among our directors so that our boardBoard has an effective mix of technical, financial, operating and management experience in our directors. We have a long-standing policyexperience. 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 keeping our board relatively small. the Board with establishing criteria for the selection of potential directors, taking into account the following desired attributes:

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We also believe that our Board should be comprised predominantly of independent directors from diverse backgrounds external to the companyCompany, but should nevertheless include the insight and judgment of our senior management; sixmanagement. Our Board has no specific requirements regarding diversity but believes that its membership should reflect a diversity of experience, gender, race, ethnicity and age. Our Board is currently 25% female, 38% ethnically diverse, and 63% female or ethnically diverse. The following diversity statistics are reported in the standardized disclosure matrix that is required by the listing rules of the Nasdaq Stock Market (“Nasdaq”):

In assessing the experience, qualifications, attributes and skills that led our seven directors are not employees.

TheNominating and Corporate Governance Committee and Board to conclude that each director has the appropriate qualifications to serve as a director of Directors unanimously recommends that the stockholders vote “FOR”Company, the proposalBoard focused on the information discussed in each of the director nominees’ individual biographies set forth on pages 10 to elect Thomas R. Stanton, H. Fenwick Huss, William L. Marks, Anthony J. Melone, Balan Nair, Roy J. Nichols13 of this Proxy Statement. In evaluating the suitability of the director nominees for re-election, our Nominating and Kathryn A. WalkerCorporate 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 directors for a one year term expiring at the 2017 Annual Meeting of Stockholders and until their successors have been duly elected and qualified.applicable.

Information Regarding the Nominees for Director

Set forth below is certain information as of January 31, 2016 regarding the seveneight 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 principal occupations.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 is set forth in the Security Ownership of Certain Beneficial Owners and Management table on page 6.

THOMAS R. STANTON has served as, age 59, was named our Chief Executive Officer and a director sincein September 2005 and as ournamed Chairman of the Board since Aprilin 2007. Prior to becoming ourHe 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. He is also the Chief Executive Officer of Adtran Networks and a member of its management board. Mr. Stanton servedjoined Adtran in 1995 as ourVice 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 – Carrier Networks from 2001of the CN Division. Prior to September 2005, Vice President and General Manager – Carrier Networks from 1999 to 2001, and Vice President – Carrier Networks Marketing from 1995 to 1999. Before joining ADTRAN, Mr. StantonAdtran, he served as Vice President –of Marketing &and Engineering forat Transcrypt International Inc. in 1995. He also served as Director, Marketing and then Senior Director, Marketing, for the E.F. held several senior management positions with E. F.

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Johnson Company from 1993 until joining Transcrypt in 1995.Company. Mr. Stanton has served on the board of directors forof a number of technology companies and is a past chairman of the Chamber of Commerce of Huntsville/Madison County, as Chairmanboard for both the Federal Reserve Bank of Atlanta’s Birmingham Branch and currently serves as Chairman for the Telecommunications Industry Association (TIA).Association. He has also served on the board of Cadence Bank (NYSE: CADE), formerly BancorpSouth Bank, since October 2015, and he is also a board member fordirector of the Economic Development Partnership of Alabama (EDPA).Alabama. In addition, Mr. Stanton previously served as a director of the Huntsville Chamber of Commerce and the Telecommunications Industry Association. Mr. Stanton holds a Bachelor of Science degree in Computer Engineering from Auburn University.

Mr. Stanton has been a member of our Board since September 2005. 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 companyCompany and extensive experience in all aspects of our industry. Mr. Stanton is 51.

H. FENWICK HUSS has, age 73, served as the Willem Kooyker Dean of the Zicklin School of Business at Baruch College, a senior college of The City University of New York, sincefrom July 1, 2014.2014 to December 2022. He is 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.

Dr. Huss has been a member of our Board of Directors since October 2002 and has served as our lead directorLead Director since May 2015. Dr. Huss also currently serves as a member of our Audit, Compensation and Nominating and Corporate Governance Committees. 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, because heenvironment. Dr. Huss also has extensive experience and knowledge of financial accounting and corporate finance and because he has management experience in the academic environment. Dr. Huss

GREGORY MCCRAY, age 60, is 65.

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WILLIAM L. MARKSan 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 June 2018, Mr. McCray has served as Chairman of the Board and Chief Executive Officer of Whitney Holding Corp.FDH Infrastructure Services (“FDH”), the holdingan engineering and science company that monitors, inspects, designs and performs structural analysis for Whitney National Bank of New Orleans, from 1990 toinfrastructure assets utilizing wireless monitoring devices and patented non-destructive testing techniques. During his retirement in March 2008, andcareer, Mr. McCray has served in variousa number of management and executive roles, including CEO of Access/Google Fiber in 2017; CEO of Aero Communications Inc., which provides installation, services and management capacities with AmSouth Bank, N.A.support to the communications industry, from 19772013 to 1990.2016; CEO of Antenova, a developer of antennas and radio frequency modules for mobile devices, from 2003 to 2012; Chairman and CEO of Piping Hot Networks, which brought broadband fixed wireless access equipment to market, from 2001 to 2002; and Senior Vice President of customer operations at Lucent Technologies from 1996 to 2000, where he managed the Customer Technical Operations Group for Europe, the Middle East and Africa. Mr. MarksMcCray currently serves on the board of directors of FDH; FreeWave Technologies; DigitalBridge Group, Inc. (NYSE: DBRG), where he serves as chairman of the Compensation Committee and a directormember of CLECO Corporationthe Nominating & Corporate Governance Committee; and CLECO Power, LLC.Belden Inc. (NYSE: BDC), and as a Life Trustee of Wake Forest University. Mr. Marks has served as a director of ADTRAN since 1993 and currentlywhere he serves as a member of our Audit, Compensationthe Finance and Nominating and Corporate Governance Committees. Mr. Marks has been selectedMcCray served as a nominee for director because of his careerCenturyLink, Inc. (NYSE: CTL), the third largest network operator in finance and financial services, because of his expertise in banking and corporate finance and because of his extensive experience as an executive and senior manager in the course of his career. Mr. Marks is 72.

ANTHONY J. MELONE has over 32 years of experience in the telecommunications industry, including havingAmerica, from January 2005 to February 2017, where he served as Executive Vice President and Chief Technology Officer for Verizon Communicationschairman of the Cyber Security & Risk Committee from December 20102015 to April 2015. In addition,2017. Mr. Melone served in a variety of positions with Verizon Wireless from 2000 to December 2010, including as Senior Vice President and Chief Technical Officer from 2007 to December 2010. Over his 32 year career with Verizon and its predecessor, Bell Atlantic, he also has served as Vice President of Network Operations and Staff Vice President of Network Planning and Administration. Since 2008, he has served as Chief Technology Officer and Senior Vice President of Rural Cellular Corporation. Mr. Melone receivedMcCray holds a Bachelor of Science degree in electrical engineeringComputer Engineering from VillanovaIowa State University and a Master of Science degree in engineeringIndustrial & Systems Engineering from Purdue University. He has also completed executive business programs at the University of Pennsylvania. Illinois, Harvard, and INSEAD.

Mr. Melone currently serves asMcCray has been a member of our Audit, Compensation and Nominating and Corporate Governance Committees.Board since May 2017. Mr. MeloneMcCray has been selected as a nominee for director because of his extensive experience as an executive and senior manager in the telecommunications industry. Mr. Melone is 55.and technology industries during the course of his career, as well as his experience as a director of publicly-held companies.

BALAN NAIR, age 57, 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

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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 for Liberty Global, Inc., a telecommunications company.from 2007 to 2017. In this capacityrole, he iswas responsible for overseeing the globalLiberty Global’s worldwide network, as well as Technology and technologyInnovation operations, which span three continentsincluding Product Development, IT, Network Operations, Mobile Operations and over 33 million homes.Global Supply Chain functions. He iswas also responsible for new product development, oversees global procurement functionsCorporate Strategy and leads Liberty Global’s Technology Investment Venture group.Investments. Mr. Nair iswas an executive officer of Liberty Global and sitssat on the company’sLiberty Global’s Executive Management CommitteeLeadership Team and the Investment Committee. Prior toBefore joining Liberty Global, in July of 2007, Mr. Nair served as AOL’s chief technology officer overseeing the company’s network operationsChief Technology Officer and back-office systems. After joiningExecutive Vice President of AOL in 2006, Mr. Nair led the Technology Operations organization in creating synergies, improving productivity, and increasing efficiencies.LLC, a global web services company. Prior to his role at AOL Mr. NairLLC, he spent more than 12 years at Qwest Communications International Inc. (Qwest), most recently as Chief Information Officer (CIO). As CIO, he was responsible for supporting Qwest’s internal and external applications, legacy systems including maintenance, internal network operations, data centers, and help desk and desktop support functions. He also headed Qwest’s technology management operations that included technical aspects of the company’s product rollouts in broadband, video, call center technology, VoIP, and wireless, among other offerings. As Qwest’s Chief Technology Officer from 2003 to 2005, he spoke often in public forums on technology and strategic topicsOfficer. Mr. Nair has a long history of working in the telecommunications industry. Mr. Nair sitstelephone, 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 Boardboard of Telenet Group Holding NV, Liberty Global’s Belgium subsidiary.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.

Mr. Nair holds a Masters of Business Administration and a Bachelor of Science in electrical engineering, both from Iowa State University. Mr. Nair is alsohas been a member of our Audit, Compensation and Nominating and Corporate Governance Committees.Board since February 2007. Mr. Nair has been selected as a nominee for director because he has extensive experience with the technologies that influence our industry and our markets and because he has management experience, particularly managing technical personnel. Mr. Nair is 49.

ROY J. NICHOLS founded and servedpersonnel, as President of Nichols Research Corporation, a defense and information systems company, where he worked from 1976 until its merger with Computer Sciences Corporation in November 1999. Mr. Nichols currently serveswell as his experience as a director of Blue Creek Investmentsa publicly-held company.

BRIAN PROTIVA, age 59, has served as an executive of Egora Ventures AG, an investment company in Munich, Germany, since October 2023. Additionally, he led Adtran Networks as Chief Executive Officer since co-founding the company in 1994 through August 31, 2022. As the CEO, he was responsible for Adtran Networks’ overall strategy, M&A and human resources and he led every department at some point during his tenure. He fully retired as an employee of Adtran Networks on December 31, 2022. Prior to co-founding and leading Adtran Networks, Mr. Protiva served as the Hudson Alpha Institutemanaging director of Biotechnology.a holding company, AMS Electronics GmbH which he converted into Egora Holding GmbH, where he also co-managed a number of its subsidiaries. In addition, Mr. NicholsProtiva has served as a directormember of ADTRANthe board of directors of AMS Technologies AG since 1994, and previously2013.

Mr. Protiva has served as our lead director from October 2006 through May 2015. Mr. Nichols is also a memberVice Chairman of our Audit, Compensation and Nominating and Corporate Governance Committees.Board since the closing of the Business Combination in July 2022. Mr. NicholsProtiva has been selected as a nominee for director because heof his 30 years of experience in the networking industry combined with his leadership skills in building Adtran Networks into a market leading optical networking company.

JACQUELINE H. (JACKIE) RICE, age 51, has extensiveserved as General Counsel 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 February 2019. Previously, she 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 has served on the board of directors of the Michigan West Coast Chamber of Commerce since October 2021. 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.

Ms. Rice has been a member of our Board since August 2016. Ms. Rice has been selected as a nominee for director because of her legal background and her experience with leadership,governance, compliance, ethics and risk assessment, information technologiesmanagement for large, publicly-held corporations.

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NIKOS THEODOSOPOULOS, age 61, served as chairman of the supervisory board of Adtran Networks from January 2015 until August 2022. He currently serves on the board of directors of Hercules Capital, Inc. and extensive knowledgepreviously served on the boards of Arista Networks from March 2014 to June 2023 and history withHarmonic Inc. 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 2022, he was an equity research analyst, primarily at UBS Group AG, 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 in Business Administration from New York University, a Master of Science from Stanford University, and a Bachelor of Science from Columbia University.

Mr. Theodosopoulos has been a member of our company.Board since the closing of the Business Combination in July 2022. Mr. Nichols is 77.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.

KATHRYN A. WALKER, age 64, 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. In addition, Ms. Walker is serving concurrently as Chief Technology Officer at Main Street Data, an agriculture data science company founded by OpenAir Equity Partners. 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 directors for SmartHome Ventures, Zubie, on the Council of Trustees at South Dakota State University and as a memberdirector of the Board of TrusteesKummer Foundation at the Missouri University of Science and Technology. Ms.��Walker currently serves as a directoralso was elected to the National Association of ADTRAN and isCorporate Directors’ Directorship 100 in 2021 in recognition of her corporate governance expertise.

Ms. Walker has been a member of our Audit, Compensation and Nominating and Corporate Governance Committees.Board since May 2014. Ms. Walker has been selected as a nominee for director because she has extensive experience with the technologies that influence our industry and our marketsmarkets. She also possesses governance expertise and because she has management experience, particularly managing technical personnel. Ms.

Voting of Proxies

Unless otherwise instructed, the proxy holders will vote proxies held by them “For” the election of Thomas R. Stanton, H. Fenwick Huss, Gregory J. McCray, Balan Nair, Brian Protiva, Jacqueline H. Rice, Nikos Theodosopoulos and Kathryn A. Walker as directors for a one-year term expiring at the 2025 Annual Meeting of Stockholders and until their successors have been duly elected and qualified. Each of the nominees has consented to serve his or her term as a director if elected. If any of the nominees should be unavailable to serve for any reason (which is 56.

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CORPORATE GOVERNANCE

Board Structure– Independent Directors

The Nominating and Corporate Governance Committee andnot anticipated), the Board of Directors have determined that Messrs. Marks, Melone, Nair and Nichols, Dr. Huss and Ms. Walker do not have any relationships that would interfere withmay designate a substitute nominee or nominees (in which event the exercise of independent judgment in carrying out their responsibilities as directors and are independent in accordance with Rule 4200(a)(15)persons named on the enclosed proxy card will vote the shares represented by all valid proxies for the election of the NASDAQ Marketplace Rules. The incumbent independent directors also constitute allsubstitute nominee or nominees), allow the vacancies to remain open until a suitable candidate or candidates are located, or by resolution provide for a lesser number of the members of the Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee. Prior to each regularly scheduled Audit Committee meeting, these directors convene and hold a separate executive session as the independent directors of the Board. Dr. Huss, our independent lead director, presides over these meetings, coordinates the activities of the independent directors and serves as liaison between the independent directors and our Chief Executive Officer and senior management. We believe this structure facilitates the development of a productive relationship with our Chief Executive Officer and ensures effective communication between our Chief Executive Officer and the independent directors.

Mr. Stanton is both our Chief Executive Officer and our Chairman; his predecessor, Mark Smith, one of our founders, also held both of these positions and we believe that having our Chief Executive Officer also holding the position of Chairman is important in underscoring his authority to our customers, our vendors and our employees and in our markets generally. We believe that this structure enhances our day-to-day operating effectiveness and does not undercut the benefits available to the Board of having separated these functions because we have established a lead director whose role is extensive and who in relationship to the other directors performs many of the functions that might otherwise be performed by a board chairman.

Meetings of the Board of Directors and its Committees

The Board of Directors conducts its business through meetingsunanimously recommends that the stockholders vote “For”

the election of the full Board and through committees of the Board, consisting of an Audit Committee, a Compensation Committee and a Nominating and Corporate eight nominees named above.

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CORPORATE GOVERNANCE

Governance Committee. During the fiscal year ended December 31, 2015, theHighlights

Our Board of Directors held seven meetings,is committed to having sound corporate governance principles. Such principles are essential to running our business efficiently and to maintaining our integrity in the Audit Committee held eight meetings,marketplace. The “Corporate Governance” section of this Proxy Statement describes our governance framework, which includes the Compensation Committee held six meetings and the Nominating and Corporate Governance Committee held three meetings. All membersfollowing features:

Composition of the Board of Directors, attended at least 75% of the aggregate of meetings of the Board of Directors and of the committees of which he or she is a member. Five of the incumbent directors attended the 2015 Annual Meeting of Stockholders on May 13, 2015.

Audit Committee

The Audit Committee is responsible for assisting the Board of Directors in fulfilling its oversight responsibilities with respect to: (1) the financial reports and other financial information provided by us to the public or any governmental body; (2) our compliance with legal and regulatory requirements; (3) our systems of internal controls regarding finance, accounting and legal compliance that have been established by management and the Board; (4) the qualifications and independence of our independent registered public accounting firm; (5) the performance of our internal audit function and the independent registered public accounting firm; and (6) our auditing, accounting and financial reporting processes generally. The Audit Committee has been established in accordance with Section 3(a)(58)(A) of the Exchange Act. In connection with its responsibilities, the Board has delegated to the Audit Committee the authority to select and hire our independent registered public accounting firm and determine their fees and retention terms. The Audit Committee operates under a charter approved by the Board. The charter is posted on our website atwww.adtran.com. The Audit Committee is composed of H. Fenwick Huss, William L. Marks, Anthony J. Melone, Balan Nair, Roy J. Nichols and Kathryn A. Walker, each of whom is independent under NASDAQ listing standards. William L. Marks is the Chair of the Audit Committee. The Board has determined that Dr. Huss is an audit committee financial expert.

Compensation Committee

The Compensation Committee is responsible for setting the compensation of our Chief Executive Officer and assisting the Board in discharging its responsibilities regarding the compensation of our other executive officers. In addition, the Compensation Committee is responsible for administering our 2015 Employee Stock Incentive Plan, our 2010 Directors Stock Plan, our Variable Incentive Compensation Plan and our Deferred Compensation Plan. The Compensation Committee operates under a charter approved by the Board. The charter is posted on our website atwww.adtran.com.The Compensation Committee is composed of H. Fenwick Huss, William L. Marks, Anthony J. Melone, Balan Nair, Roy J. Nichols and Kathryn A. Walker, each of whom is independent under NASDAQ listing standards. Mr. Nair is the Chair of the Compensation Committee.

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Compensation Committee Process

Under our Compensation Committee’s charter, the Committee has the power and duty to discharge our Board’s responsibilities related to compensation of our executive officers, within guidelines established by the Board. Generally, the Compensation Committee reviews and approves all compensation, including base salary, annual incentive awards and equity awards, for the Chief Executive Officer and our other officers. The Compensation Committee also makes recommendations to the Board regarding our incentive compensation plans and equity plans, and approves equity grants. The Committee has authority to review and approve annual performance goals and objectives for our Chief Executive Officer, to evaluate his performance and to set his compensation based on the evaluation. The Committee is also responsible for reviewing and approving executive officers’ compensation and establishing performance goals related to their compensation within 90 days of the beginning of each fiscal year. The Committee oversees our benefit plans and evaluates any proposed new retirement or executive benefit plans. The Committee also advises the Board on trends in compensation programs for non-employee directors. The Compensation Committee has the authority to delegate its duties to subcommittees, but to date has not done so. In accordance with Delaware law, in November 2015 the Compensation Committee also delegated to the Chief Executive Officer the authority to approve individual incentive stock option awards to employees of ADTRAN who are not officers, subject to a maximum aggregate limit of 979,660 stock options, andpre-approved terms and conditions.

At the beginning of each calendar year, our Compensation Committee reviews the variable incentive cash compensation (“VICC”) program results from the prior year and approves any payouts thereunder, establishes the performance goals for the current year, approves any increases in executive salaries or other compensation, recommends plan changes, if any, for submission to our stockholders at the annual meeting, and approves the Compensation Committee’s report for our proxy statement. Mid-year the Compensation Committee generally reviews our compensation programs and makes recommendations to the Board regarding outside director compensation and, as necessary throughout the year, approves any equity awards and/or compensation for newly hired or promoted executives. Our Compensation Committee generally meets in the latter part of each calendar year to determine and approve annual equity awards.

Our Compensation Committee generally receives proposals and information from our Chief Executive Officer for its consideration regarding executive and director compensation. Our Chief Executive Officer makes recommendations regarding salary increases, annual cash incentives and equity awards for all of our executive officers other than himself. In doing so, he consults with our Chief Financial Officer.

Our Compensation Committee has authority to retain and terminate any outside advisors, such as compensation consultants. Though our Compensation Committee has not historically employed compensation consultants to assist it in designing our compensation programs, the Committee did engage Towers Watson in 2008 and again in 2011 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. This methodology, in combination with our own research and analysis, remains a part of the process the Compensation Committee undertakes each year in determining compensation of our executives and directors. See “Executive Compensation – Compensation Discussion and Analysis – Overview and Philosophy.”

Compensation Committee Interlocks and Insider Participation

None of our executive officers or directors serves as a member of the board of directors or compensation committee of any entity that has one or more of its executive officers serving as a member of our Board of Directors or Compensation Committee.

Nominating and Corporate Governance Committee

The Nominating and Corporate Governance Committee is responsible for assisting the Board in identifying and attracting highly qualified individuals to serve as directors of ADTRAN, selecting director nominees and recommending them to the Board for election at annual meetings of stockholders. The Nominating and Corporate Governance Committee operates under a charter approved by the Board. The charter is posted on our website atwww.adtran.com.The Nominating and Corporate Governance Committee is composed of H. Fenwick Huss, William L. Marks, Anthony J. Melone, Balan Nair, Roy J. Nichols and Kathryn A. Walker, each of whom is independent under NASDAQ listing standards. Ms. Walker is the Chair of the Nominating and Corporate Governance Committee.

Consideration of Director Nominees

The Nominating and Corporate Governance Committee seeks to create aensure that the Board, that as a whole, is strong in its collective knowledge of, and has a diversity of skills and experience with respect to, accounting and finance, management and leadership, vision and strategy, business operations, business judgment, crisis management, risk assessment, industry knowledge, corporate governance and global markets. As part of our annual Board self-evaluation process, the Board evaluates whether or not the Board as a whole has the appropriate mix of skills, experience, backgrounds and diversity in relation to the needs of the Company for the current issues facing the Company.

Directors to be nominated by the Company for election at the annual stockholders’ meeting are approved by the Board upon recommendation by the Nominating and Corporate Governance Committee. The Nominating and Corporate Governance Committee considers candidates for Board membership from recommendations by third-party executive search firms and candidates recommended by stockholders and by management, as well as recommendations from its committee members and other members of the Board. When the Nominating and Corporate Governance Committee reviews a potential new candidate, the Committee looks specifically at the candidate’s qualifications in light of the needs of the Board and ADTRANthe Company at that time given the then current mix of director attributes.

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In accordance with NASDAQ listing standards, we ensure that at least a majority of our Board is independent under the NASDAQ definition of independence, and that the members of the Board as a group maintain the requisite qualifications under NASDAQ listing standardsProcess for populating the Audit, Compensation and Nominating and Corporate Governance Committees. The Board has adopted Corporate Governance Principles that set forth the principles that guide us and the Board on matters of corporate governance. The Corporate Governance Principles are posted on our website atwww.adtran.com.Stockholders to Recommend Director Nominees

As provided in its charter, the Nominating and Corporate Governance Committee will consider nominationspotential director candidates submitted by stockholders. To recommend a nominee, a stockholder should write to the Nominating and Corporate Governance Committee care of Roger D. Shannon,at ADTRAN Holdings, Inc., Attn: Corporate Secretary, of ADTRAN, at 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:

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To be considered byThe Corporate Secretary will promptly forward these materials to the Chair of the Nominating and Corporate Governance Committee for nomination and inclusion in our proxy statement for the 2017 Annual Meeting, stockholder recommendations for director must be received by us no later than December 5, 2016. Once we receiveChairman of the recommendation, we will deliverBoard. The Nominating and Corporate Governance Committee may contact a questionnairerecommended candidate to the candidate that requestsrequest 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 “Corporate 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.

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Board, Committee and Individual Director Evaluation Program

Pursuant to the Corporate Governance Principles, the Board and each of its committees conduct an annual evaluation of its performance, led by the Nominating and Corporate Governance Committee. The evaluation is intended to determine whether the Board and its committees are functioning effectively and fulfilling the requirements set forth in the Corporate Governance Principles or the committee’s charter, as applicable. Beginning in 2018, the evaluations also included self-evaluations pursuant to which the directors were asked to examine their own contributions to the Board or committee, as appropriate, and potential areas of improvement. The Nominating and Corporate Governance Committee formalized the following self-evaluation program, with the goal of placing additional emphasis on improvements to processes and effectiveness:

				Board and Committee members complete self-evaluations: These questionnaires are completed individually in order to encourage honest feedback from the directors.
				Group discussions: The Board or committee, as applicable, engages in a discussion of the completed questionnaires in order to assess performance in areas such as meeting efficiency, membership and structure, culture and operational effectiveness, and execution of roles and responsibilities.
				Focus on outcomes: The Nominating and Corporate Governance Committee discusses the outcomes of the Board and committee evaluations, determines appropriate follow-up action items and assigns responsibility for such actions.

The Company used an independent third party to provide an annual evaluation designed to ensure feedback and continuous improvement.

Corporate Governance Principles

The Board of Directors has adopted Corporate Governance Principles that set forth the Company’s fundamental corporate governance principles and provide a flexible framework for the governance of the Company. The Corporate Governance Principles address, among other things, Board duties and responsibilities, management development and succession planning, Board membership and independence, Board meetings and Board committees, access to senior management and experts, director orientation and continuing education, and annual performance evaluations. The Nominating and Corporate Governance Committee regularly reviews and reassesses the adequacy of the Corporate Governance Principles and recommends any proposed changes to the Board, and the full Board approves such changes as it deems appropriate. A copy of our Corporate Governance Principles is available in the “Corporate Governance” section of our website at https://investors.adtran.com.

Director Independence

Nasdaq listing standards require that the Company have a majority of independent directors. Accordingly, because our Board currently has eight members, Nasdaq requires that five or more of the directors be independent. Nasdaq’s listing standards provide that no director will qualify as “independent” for these purposes unless the Board affirmatively determines that the director has no relationship with the Company that would interfere with the exercise of the director’s independent judgment in carrying out the responsibilities of a director. Additionally, the listing standards set forth a list of relationships that would preclude a finding of independence.

The Board affirmatively determines the independence of each director and nominee for election as a director. The Board makes this determination annually. In accordance with Nasdaq’s listing standards, we do not consider a director to be independent unless the Board determines that (i) no relationship exists that would preclude a finding of independence under Nasdaq’s listing standards and (ii) the director has no relationship with the Company (either directly or as a partner, stockholder or officer of an organization that has a relationship with the Company) that would interfere with the exercise of the director’s independent judgment in carrying out his or her

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responsibilities as a director. Members of the Audit, Compensation and Nominating and Corporate Governance Committees must also meet applicable independence tests of Nasdaq and the SEC. Additionally, the charter of the Environmental, Social and Governance (“ESG”) Committee requires that its members also be independent under Nasdaq’s listing standards.

The Board has reviewed a summary of directors’ responses to a questionnaire asking about their relationships with the Company, as well as certain informationmaterial provided by management related to transactions, relationships or arrangements between the Company and the directors and parties related to the directors. Following this review, the Board determined that mustsix of the eight directors (Dr. Huss, Mr. McCray, Mr. Nair, Ms. Rice, Mr. Theodosopoulos and Ms. Walker) are independent. Additionally, the Board determined that each current member of the Audit, Compensation, Nominating and Corporate Governance, and ESG Committees, as well as each director who served on any of the committees during 2023, also satisfies the independence tests referenced above. In determining the independence of Mr. Nair, who serves as President and Chief Executive Officer of Liberty Latin America Ltd., the Board considered that we have maintained customer relationships with several Liberty Latin America affiliates for some time. Our sales to the Liberty Latin America affiliates are in the ordinary course of business and relate to arms’ length purchase orders submitted by Liberty Latin America affiliates. The amounts received by us from Liberty Latin America affiliates in each of the past three years were less than 1.0% of our consolidated gross revenues in each such year and less than 0.1% of Liberty Latin America’s operating costs and expenses. Liberty Latin America is not considered one of our significant customers. Accordingly, it was determined that Mr. Nair does not have a direct or indirect material interest in the Company’s relationship with Liberty Latin America.

Company Leadership Structure

The Board of Directors oversees the business and affairs of the Company and monitors the performance of its management. The basic responsibility of the Board is to lead the Company by exercising its business judgment to act in what each director reasonably believes to be disclosedthe best interests of the Company and its stockholders. Although the Board is not involved in the Company’s day-to-day operations, the directors keep themselves informed about the candidate in the proxy statement, if nominated. Candidates must complete and return the questionnaire within the time frame provided to be considered for nomination by the Committee.

AllCompany through meetings of the current nominees for director recommendedBoard, reports from management and discussions with the Company’s NEOs. Directors also communicate with the Company’s outside advisors, as necessary.

The Board does not have a policy as to whether the role of Chair of the Board and Chief Executive Officer should be separate or whether the Chair should be a management or a non-management director. The Corporate Governance Principles provide that whether to have the same person occupy the offices of Chair and Chief Executive Officer should be decided by the Board, for electionfrom time to time, in its business judgment after considering relevant circumstances. If the Chair is also the Chief Executive Officer, or if the Board otherwise determines that it is appropriate, the Board will also elect an independent lead director (as described below). Thomas R. Stanton has held the roles of Chairman and the Company’s Chief Executive Officer since 2007 and Brian Protiva has served as Vice Chairman of the Board since the closing of the Business Combination in July 2022. The Board believes that this leadership structure promotes strategy development and execution, and facilitates information flow between management and the Board.

The Board has determined that it is in the best interests of the Company and its stockholders to elect an independent director to serve in a lead capacity (the “Lead Director”) to perform the duties and responsibilities set forth in the Corporate Governance Principles and as determined by the stockholders atBoard. The Board elected H. Fenwick Huss as the 2016 Annual Meeting are currentLead Director in May 2015. Dr. Huss presides over the regular executive sessions of the independent directors, serves as a liaison between the independent directors and the Chairman and Vice Chairman, and presides over the Board’s annual evaluation of the Chief Executive Officer, among other duties. We believe this structure facilitates the development of a productive relationship between the independent directors and the Chairman and Vice Chairman and ensures effective communication between the Board and management.

Board Structure and Committees

The Board of Directors conducts its business through meetings of the full Board and through committees of the Board, consisting of an Audit Committee, a Compensation Committee, a Nominating and Corporate Governance Committee and an ESG Committee. The Board may from time to time form other committees as circumstances warrant. Such committees will have the authority and responsibility as delegated by the Board. Only members of the Board can be members of a committee, and each committee is required to report its actions to the full Board.

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Each committee operates under a written charter adopted by the Board, which are available in the “Corporate Governance” section of our website at https://investors.adtran.com. The Nominating and Corporate Governance Committee is responsible for evaluating the membership of the committees and making recommendations to the Board regarding the same, which it does annually following a review of the Board’s current competencies. This periodic review of each director’s specific skills and experience allows the Nominating and Corporate Governance Committee to ensure that the committees are organized for optimal effectiveness.

The Board met 15 times in 2023. None of the incumbent directors attended less than 75% of the aggregate of (a) the total number of meetings held in 2023 of the Board while he or she was a director and (b) the total number of meetings held in 2023 of all committees of the Board on which he or she served. Absent extenuating circumstances, directors are expected to participate in annual meetings of the Company’s stockholders, and all of our directors serving at that time attended the 2023 Annual Meeting of Stockholders.

The following table sets forth the current membership and the roles and responsibilities of each committee of the Board, as well as the number of meetings that each committee held during 2023:

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Risk Management and Cybersecurity Oversight

Enterprise Risk Management

Our management continually monitors the material risks facing the Company, including financial risk, strategic risk, operational risk, and legal and compliance risk. The Board of Directors is responsible for overseeing management’s identification and management of, and planning for, those risks. The Board has delegated to certain committees oversight responsibility for those risks that are directly related to their areas of focus. The Audit Committee is responsible for coordinating the Board’s oversight of the Company’s risk management program, including the process by which management assesses, prioritizes and manages the Company’s material risks. The Audit Committee also oversees the major financial, data security and enterprise risks facing the Company. The Compensation Committee considers risk issues when establishing and administering our compensation program for executive officers and other key personnel. The Nominating and Corporate Governance Committee oversees matters relating to the composition and organization of the Board and advises the Board on how its effectiveness can be improved by changes in its composition and organization. The ESG Committee discusses with management and the Board the Company’s material ESG-related risks and the Company’s implementation of appropriate strategies to manage such risks, as well as the Company’s compliance with the various global environmental, health and safety standards and initiatives that are applicable to our business segments. The Board and its committees exercise their risk oversight function by carefully evaluating the reports they receive from management and by making inquiries of management with respect to areas of particular interest to the Board or committee.

Cybersecurity Oversight

Cybersecurity is a critical part of the Company’s risk management. To more effectively address cybersecurity threats, the Company leverages a multi-layered approach, led by a Chief Information Officer / Chief Information Security Officer whose team is responsible for leading enterprise-wide information security strategy, policy, standards, architecture and processes. Both the Board and the Audit Committee each receive regular updates from senior management, including the CISO and cybersecurity experts, in areas such as threat intelligence, major cyber risk areas, emerging global policies and regulations, cybersecurity technologies and best practices, and cybersecurity incidents. Highlights of the Company’s cybersecurity efforts and achievements are as follows:

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Corporate Social Responsibility and Sustainability

As we follow our vision to “enable a fully connected world,” corporate social responsibility (CSR) and environmental, social and governance (ESG) matters are important to us. As more people are connected, work and life can be accomplished using fewer resources. On the journey to our vision, we must continue to be a responsible corporate citizen of the world. We have established ESG and sustainability programs and policies that encompass the elements of Environmental, Health & Safety, Ethics, Labor, and Management Systems in alignment with the ISO 26000 Guidelines. We are committed to operating in full compliance with the laws, rules and regulations of all the countries in which we operate. Adtran recognizes the Responsible Business Alliance (RBA) Code of Conduct (the “Code”) and actively pursues conformance to it and its standards in accordance with our management systems. Adtran further recognizes the Code as a total supply chain initiative.

We have an established Sustainability Committee comprised of members of senior management in the areas of engineering, sales, research and development, strategic planning, software and solutions quality, corporate compliance, and supplier quality engineering and environmental, among others. This working group meets monthly to establish our sustainability strategy and monitor progress toward these goals. Additionally, the ESG Committee of the Board has been formally tasked with overseeing management’s efforts related to the long-term sustainable growth of the Company, including considering the social and environmental goals of the Company. We use the European Sustainability Reporting Standards (ESRS) for our ESG reporting, and these standards support our ESG risk, materiality and context assessments. Highlights of our current practices in these areas are described below.

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Equity Ownership Requirement for Non-Employee Directors

In evaluating candidatesMarch 2020, the Board of Directors adopted stock ownership guidelines for non-employee directors effective January 1, 2020. The Outside Director Stock Ownership Guidelines require each director to hold shares of the Committee usesCompany’s common stock with a value equal to at least three times the qualifications described above,director’s regular annual cash retainer. Directors have until the later of January 1, 2025 and evaluates stockholder candidatesfive years from the date of such director’s election to meet the ownership requirement. The minimum number of shares to be held by a director will be calculated during the first calendar quarter of each fiscal year based on the director’s annual cash retainer in effect as of December 31^st of the preceding year. The value of shares held by a director will be deemed to be the greater of (i) fair market value on the last trading day of the immediately preceding calendar year and (ii) fair market value on the date of acquisition of each share held. Any subsequent change in the value of the shares will not affect the amount of stock directors should hold during that year. For purposes of meeting the ownership guidelines, the following categories of stock are counted: (i) shares owned outright by the director or his or her immediate family members residing in the same manner as candidates from all other sources. Based onhousehold; (ii) shares held in trust or custody for the Committee’s evaluation of each nominee’s satisfactionbenefit of the qualifications described abovedirector or one or more members of his or her family; and his prior performance(iii) shares (or units representing shares) held in a deferred compensation account under the Equity Deferral Program for Directors or other similar deferral plans. If the number of shares that a director should own is increased as a result of an increase in the amount of such director’s annual retainer, the director will have five years from the effective date of the increase to attain the increased level of ownership.

Directors must refrain from selling or transferring shares of the Company’s common stock until they have first satisfied the stock ownership requirement. Once a director has met the stock ownership requirement, if there is a subsequent decline in the Company’s stock price that causes the director’s ownership level to fall below the guideline, the director is not required to purchase additional shares but is generally required to refrain from selling or transferring shares until the guideline is again satisfied. The Outside Director Stock Ownership Guidelines are available in the “Corporate Governance” section of our website at https://investors.adtran.com.

Compensation Committee determined to recommend each incumbent director for re-election.The CommitteeInterlocks and Insider Participation

None of our executive officers or directors serves as a member of the board of directors or compensation committee of any entity that has not received any nominations from stockholders for the 2016 Annual Meeting.one or more of its executive officers serving as a member of our Board of Directors or Compensation Committee.

Communications with the Board of Directors

Stockholders and other interested parties may communicate with the Board, the non-management directors or specific directors by mail addressed to: ADTRAN Holdings, Inc., Attn: Corporate Secretary, 901 Explorer Boulevard, Huntsville, Alabama 35806. The communication should clearly indicate whether it is intended for the Board, the non-management directors or a specific director. Our Corporate Secretary will review all communications and will, on a periodic basis, forward all communications to the appropriate director or directors, other than those communications that are merely solicitations for products or services or that relate to matters that are clearly improper or irrelevant to the Board’s responsibilities.

The Board has also established a process for stockholders to communicate withconcerns to members of the Board.Board on a confidential basis. If you have any concern, question or complaint regarding any accounting, auditing or internal controls matter, as well as any issues arising under our Code of Conduct and Ethics or other matters that you wish to communicate to ADTRAN’sour Audit Committee or Board of Directors, you can reach the ADTRAN Board of Directors through our Corporate Governance Hotline by emailonline at hotline@adtran.com, by mailhttps://www.report.whistleb.com/Adtran (Client Code: 453581) or via phone to WhistleB at ADTRAN, Inc. Hotline, P.O. Box 5765, Huntsville, Alabama 35814, or by calling the hotline at 1-888-723-8726 (1-888-7ADTRAN)1.800.218.8954 (Client Code: 453581). Information about the Corporate Governance Hotline can be found onin the “Corporate Governance” section of our website atwww.adtran.com under the links “Investor Relations – Corporate Governance.”

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EXECUTIVE COMPENSATION

Compensation Discussion and Analysis

OverviewExecutive Summary

This Compensation Discussion and Analysis is designed to provide our stockholders with an explanation of our executive compensation philosophy and objectives, our 2023 executive compensation program and the compensation paid by us to the following named executive officers (or “NEOs”): Thomas R. Stanton, Chief Executive Officer (“CEO”); Ulrich Dopfer, Senior Vice President, Chief Financial Officer, Corporate Secretary and Treasurer;James D. Wilson, Jr., Chief Revenue Officer; Christoph Glingener, Chief Technology Officer of the Company and former CEO of Adtran Networks; and Michael K. Foliano, Former Senior Vice President of Finance, Chief Financial Officer, Treasurer and Secretary (who retired from the Company effective June 28, 2023).

Compensation Philosophy

The goalsguiding principles of our executive compensation program are to:

provide balance to project against risks.

We design our executive compensation programspackages in a manner that incorporates these principles. We also evaluate the compensation packages to ensure they will help us achieve these goals. For instance,encourage executive management to deliver strong performance results in the compensation year under consideration and motivate management to realize our strategic initiatives within the immediate, near and long-term time frames our directors and management have developed. Additionally, we consider retentionvarious market performance metrics in order to be a very important considerationput the executive compensation program in context, including the performance of the Company in prior periods, the performance of the industry and our compensation programs,competitors in those periods, and internal promotion and retention of key executive talent has been a longstanding practice oftotal stockholder return (“TSR”), particularly as relative to our company. peer companies over those periods.

We believe that retention involves two interrelated components – maintainingalso maintain a positive working environment that provides intangible benefits to our executives and encourages longevity and providing total compensation that is generally competitive within our industry and among companies of comparable size and complexity. Augmentinglongevity. Combining compensation with a desirable working environment enablesallows us to maintain a compensation program that generally provides overall compensation to our executive officers that is approximately at the median when compared to companies with which we compete for talent,talent.

Compensation in Context: Discussion of 2023 Financial Results and Operating Activities

Aligning executive compensation with stockholder interests is a primary consideration in determining our executive compensation program. Accordingly, we believe that Company performance and stockholder returns are important factors to consider when making executive compensation decisions. We use TSR, measured over rolling three-year periods relative to a broad-based industry peer group, as the measure for our performance-based equity compensation. Additionally, we believe that motivating executives to achieve certain performance targets used in our annual incentive compensation programs leads to positive stockholder returns. Below are some of the Company’s key financial and operating performance accomplishments during 2023:

Business Results:

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Financial Results:

All of this was accomplished despite customer spending continuing to be negatively impacted by excess inventory and the weakened macroeconomic environment related to continued elevated interest rates and ongoing inflationary pressures. Despite these challenges, we continue to see increasing investment from both public and private sectors in fiber-based broadband connectivity and capacity upgrades in the network infrastructure in our primary growth markets in the U.S. and Europe. The growth in fiber broadband is further increasing the demand for cloud-managed mesh Wi-Fi solutions and software solutions to improve in-home wireless connectivity while streamlining network operations. We believe that it also drives bandwidth consumption in backhaul, metro and core networks, fueling the demand for our optical networking solutions.

As a result of ongoing uncertainty around the current macroeconomic environment and its impact on customer spending levels during the second half of 2023, the Company’s management implemented the Business Efficiency Program in November 2023. In connection with the Business Efficiency Program, on December 1, 2023, the Compensation Committee authorized temporary base salary reductions for the Company’s executive officers (as described below), which reductions are effective through July 31, 2024.

Overview of Executive Compensation Program

Our executive compensation packages are comprised of base salary and incentive opportunities, which can be annual or long-term and paid in cash or equity. We use a mix of these incentives to align management’s interests with those companies.of our stockholders. In designing incentive compensation packages, we use performance measures related to the Company’s financial goals, as well as the Company’s TSR, all with the goal of increasing stockholder return. We also individualize certain performance measures for individual executives.

Beginning with an in-depth reviewSpecific considerations in 2008, the BoardCompensation Committee’s process in setting 2023 executive compensation included the following:

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The compensation of our NEOs is comprised of the following elements:

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Role of the Compensation Committee and senior management have continually workedManagement

Under our Compensation Committee’s Charter, the Compensation Committee has the power and duty to establishdischarge our Board’s responsibilities related to compensation of our executive officers, within guidelines established by the Board. The Compensation Committee reviews and maintainapproves compensation, including base salary, annual incentive awards and equity awards, for the Chief Executive Officer and our other executive officers. The Compensation Committee also makes recommendations to the Board regarding our incentive compensation plans and equity plans and approves equity grants. The Committee has the authority to review and approve annual performance goals and objectives for our Chief Executive Officer and to set his compensation based on an evaluation of his performance conducted by the Board under the direction of the Lead Director. The Committee is also responsible for reviewing and approving executive officers’ compensation and establishing performance goals related to their compensation.

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”) programs and the standards for measuring achievement of typesthose goals, approves any increases in executive salaries or other compensation, approves the annual equity grants, and recommends plan changes, if any, for submission to our stockholders at levels that are competitive withinthe annual meeting. Mid-year, the Compensation Committee generally reviews our industrycompensation programs and makes recommendations to the Board regarding outside director compensation and, as necessary throughout the year, approves any equity awards and/or compensation for newly hired or promoted executives.

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. Adtran Networks has a similar committee with employee representation responsible for overseeing such entity’s benefit and retirement plans.

Our Chief Executive Officer works closely with the Compensation Committee to maintain an open dialogue regarding the Compensation Committee’s goals, progress towards achievement of those goals and expectations for future performance. The Chief Executive Officer updates the Compensation Committee regularly on results and various compensation issues. Our Chief Executive Officer also provides the Committee, and in particular, the Committee Chair, with recommendations regarding compensation for our executive officers other than himself. The Compensation Committee considers the recommendations from the Chief Executive Officer when approving pay changes for executives managersother than the Chief Executive Officer. The Compensation Committee has delegated to the Chief Executive Officer the authority to approve the base salaries and directors.incentive compensation of non-executive employees, as well as equity grants to such individuals, subject to pre-approved limits and terms and conditions. In 2008 and again in 2011,part because the Chief Executive Officer works closely with the Committee retainedthroughout the year, the Committee is in a position to evaluate his performance and make its own determinations regarding appropriate levels of compensation consulting firmfor the Chief Executive Officer.

Role of Towers Watsonthe Compensation Consultant

Our Compensation Committee has the authority to retain and terminate any outside advisors, such as compensation consultants. Starting in 2022, the Committee engaged Pay Governance LLC, an independent compensation consultant, at various times to provide compensation information and analysis with respect toof our executive compensation in the context of the telecom industry and to our peer companies withinin the industry.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 below in connection with determining the 2023 compensation arrangements of our NEOs:

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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 considered information collected by senior management and the Committee fromreferences various peer, industry and other sources, surveys and databases,market compensation data when evaluating the appropriateness of the Company’s compensation program, including publicly availablethe compensation information of other companies, both those with which we compete and those within our geographic labor market, to gauge the competitivenessarrangements of our compensation programs. Having determined at the time of these studies that our compensation levels for some senior managers were not competitive within the telecom industry or among our peers, the Committee recommended that compensation for these positions should be increased toward a more competitive level in multiple steps over a reasonable time period. The Board concurred, and each year the Committee continues to guide executive and director compensation to achieve this goal.NEOs.

The Compensation Committee awards equity compensation after taking into accountreviews the Company’s absolutetypes of services provided by Pay Governance and relative performance, in additionall fees paid for those services on a regular basis. Neither Pay Governance nor any of its affiliates provided additional services to the industry and peer group compensation benchmarks. The compensation decisions madeCompany or any of its affiliates in 2015 for senior managers continue2023, other than the theme and represent another step toward attaining more competitive levels of compensation.

In additionadvice provided by Pay Governance to the analysis with Towers Watson conducted in each of 2008 and 2011, as described above, in 2010, the Compensation Committee undertook a reviewon director compensation and the advice provided to the Company on pension plan management, company insurance and employee health insurance. 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 conflict of interest in 2023. 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.

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 certain officerscompetitive practice in order to assist in attracting and management employees.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, of this review,we also use Company and individual performance in determining the appropriate compensation opportunities for our NEOs.

Our Compensation Committee determined that, to better incentivize officers and managers and to attract and retain qualified executives, the Board, among other things, should consider increasing the maximum performance award that may be granted in a plan year. To effectuate this change, effective January 1, 2011, the Company revised its VICC program for executives under the ADTRAN, Inc. Variable Incentive Compensation Plan (the “Variable Incentive Compensation Plan”) and adopted a group of VICC programs designed to encourage and reward growth in pretax income, and in various categories of revenue. The Variable Incentive Compensation Plan was then approved by the Company’s stockholders and adopted by the Company at the 2011 annual meeting. Under the Variable Incentive Compensation Plan as adopted by the Company, the maximum performance award that may be granted to any recipient for any plan year was increased to $3,000,000.

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The Compensation Committee also focuses on to 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:

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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.

Our Chief Executive Officer works closely withRisk 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 maintainhave 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 open dialogue regardingexecutive 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.

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Our “Say-on-Pay” Results from Last Year and Our Response

Stockholder Letter from the Compensation Committee’s goals,Committee

Dear Stockholders,

I hope this letter finds you well. I am writing to address the outcome of the stockholder vote on the Company’s executive compensation plan taken at the 2023 Annual Meeting of Stockholders, commonly referred to as “Say-on-Pay.” The Compensation Committee is committed to maintaining a strong and transparent dialogue with our stockholders, and we take all concerns and feedback seriously.

First and foremost, we would like to express our gratitude for your active participation and engagement in this critical aspect of our corporate governance. Your votes and opinions play a vital role in shaping our compensation policies, and your involvement underscores the importance of responsible stewardship.

It is with regret that we acknowledge the outcome of the Say-on-Pay vote in 2023, which indicated that a majority of our stockholders (53%) did not support our executive compensation plan. We understand that this result reflects concerns about various aspects of our compensation program, including its alignment with performance, competitive benchmarks, and stockholder interests.

The Compensation Committee and the Board of Directors are deeply committed to addressing these concerns and ensuring that our executive compensation practices are both competitive and aligned with the long-term interests of our stockholders. To address these concerns, we are taking the following steps:

We want to assure you that our commitment to responsible corporate governance remains unwavering. We understand that our compensation programs must be designed to attract, retain, and motivate talented executives while also being accountable to our stockholders. We believe that, by addressing the concerns raised by this vote, we can enhance the alignment of our executive compensation practices with the long-term success of the Company.

Your trust in our Company is invaluable, and we remain dedicated to earning and preserving that trust. We are committed to working diligently to address the issues raised by the failed Say-on-Pay vote and to ensuring that our compensation practices are consistent with the best interests of our stockholders. You will see our progress towards achievementin this Compensation Discussion and Analysis section.

Thank you for your continued support and engagement. We look forward to ongoing dialogue and collaboration as we strive to improve our executive compensation practices.

Sincerely,

Nikos Theodosopoulos

Chair of those goals and expectations for future performance. The Chief Executive Officer updates the Compensation Committee, regularly on results and compensation issues. Our Chief Executive Officer also providesbehalf of the Compensation Committee

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Stockholder Outreach and in particular,Response

Considering the Committee Chair, with recommendations regarding compensation for our executive officers other than himself. In part becauseSay-on-Pay vote result from the Chief Executive Officer works closely with2023 Annual Meeting of Stockholders, the Compensation Committee throughoutcommissioned an outreach program to identify and assess the year,items of concern for our stockholders. This process included meetings with interested stockholders to identify and catalog their concerns, followed by an assessment of the most prevalent issues to determine what actions may be required. The program was broad-based, focusing on institutional investors and supplemented with feedback from shareholder advisory services. We contacted 30 investors holding 73.6% of our outstanding shares and received feedback from 20 investors holding 64.0% of our outstanding shares, as illustrated below:

The stockholder outreach meetings were attended at various times by the Chair of our Compensation Committee, our Chief Financial Officer, and our Vice President, Investor Relations, and from the investor side, the meetings were attended by Managing Directors, Fund Managers, Corporate Governance Teams, Stewardship Teams, and Proxy Review Teams.

The investors provided feedback on the following items, in order of most cited to least cited, and here is what we have done in response:

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The Committee also extended the measurement period for the short-term cash incentive program from quarterly performance periods to a half-year performance period in the second half of 2023, and currently intends to use a one-year measurement period going forward.

We also engaged with and received feedback from two of the largest and most reputable shareholder advisory services. Their feedback was closely aligned with what we heard from our shareholders during the outreach process.

In light of the slowing of customer demand during 2023 and the effect on revenues, on December 1, 2023, the Committee approved reductions to the base salaries of certain officers and other highly-compensated employees that are expected to extend until July 31, 2024. The CEO’s base salary was reduced by 50%, other NEO salaries were reduced by 25%, and other highly-compensated individuals were reduced between 5% and 15% depending on their current base salary. These reductions to the NEO salaries are reflected in the Summary Compensation Table on page 47.

In summary, the Compensation Committee is incommitted to maintaining a positionstrong and transparent dialogue with our stockholders, and the Committee takes concerns and feedback seriously. The Committee has developed and implemented a process to evaluate his performancecollect and make its own determinations regarding appropriate levels ofassess stockholder feedback and has addressed this feedback through changes to the compensation for the Chief Executive Officer.

Appointment of New Chief Financial Officer

In 2015, we appointed Roger D. Shannon as our new Chief Financial Officer. In connection with Mr. Shannon’s hiring, his compensation includes a base salary of $365,000, a make-whole bonus as discussed below, provision for incentive awards, as discussed below,system where it makes sense. The Committee will continue to review feedback and reimbursement for certain relocation expenses, which relocation expenses must be repaid if he voluntarily leaves the Company, other than for Good Reason, or does not relocate his family, in each case, within the first twelve months of employment. In his prior employment, Mr. Shannon was a participant in a bonus program and to compensate him for amounts he would be foregoing to join the Company, we designed the one-time make-whole bonuses described below. We agreed to pay Mr. Shannon the make-whole bonus, structured as follows: (i) a one-time payment of $220,000, payablebest practices in the first quarterfuture to ensure alignment.

Elements of 2016, which he must repay if he voluntarily leaves the Company, other than for Good Reason, or does not relocate his family, in each case, within the first twelve months of employment; and (ii) a one-time payment of $109,500, payable in the first quarter of 2017, which will be reduced on a dollar-for-dollar basis by any amount that Mr. Shannon earns for 2016 under the Company’s VICC program, and which he will only be entitled to receive if he is still employed by the Company in the first quarter of 2017. Under the terms of Mr. Shannon’s offer letter, the term “Good Reason” means a significant decrease in his base compensation, a decrease in his title and/or responsibilities, a change in his reporting to a position other than the CEO of the Company, or a requirement that he move to a work location more than 25 miles from the Company’s current headquarters.

Mr. Shannon’s offer letter also included the following long-term incentive equity awards: (1) An initial stock option grant of 30,000 options with an annual ratable four-year vesting term and (2) an initial performance restricted stock unit award of 5,200 shares, all of which-vest at the end of the three-year performance period based on the company’s relative total shareholder return, or “TSR” performance against the NASDAQ Telecommunications Index.

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Components of2023 Executive Compensation

Our executive compensation program consists of base salary, commissionssalary; short-term cash incentives, including those under our VICC program, a sales incentive arrangement for sales executives, an annual VICC program,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 2023, the Compensation Committee continued to grant performance-based PSUs to the NEOs that are eligible to be earned based on a financial performance measure over a three-year performance period and granted one-time “integration awards” to the NEOs that are eligible to be earned based on the achievement of cost savings targets related to the Business Combination over a two-year performance period. Finally, the Committee granted one-timestock options and performance-based restricted stock units. Executive officersto Mr. Wilson in connection with his temporary salary reduction, which was approved by the Committee on December 1, 2023.

Our U.S.-based NEOs also are eligible to participate in a nonqualified deferred compensation program (and the Board approved the inclusion of directors in this program beginning in 2010)Company’s Deferred Compensation Plan and in certain benefit programs that are generally available to all of our employees, such as medical insurance programs, life and disability insurance programs and our 401(k) plan. The

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 the Company’s principal accounting officer and Corporate Secretary and Treasurer on May 10, 2023. 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. Although each of Mr. Dopfer’s and Dr. Glingener’s compensation is now determined by the Company’s Compensation Committee, it must still be approved each year by the Adtran Networks supervisory board (which is similar to the board of our Board of Directors oversees our executive compensation program.directors for a U.S. company) pursuant to each individual’s employment agreement. See “Employment Arrangements” below for additional detail on these employment agreements.

Base Salary and Commissions.

Base salaries are the most basic form of compensation and 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 as well as commission structures for our sales executives, based on recommendations made by our Chief Executive Officer in consultation with respect to the salaries of our Chief Financial Officer.other executives. Consistent with our compensation objectives and philosophy described above, the Compensation Committee attempts to set sets

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base salary compensation, and adjustadjusts it when warranted, based on companythe Company’s financial performance, the individual’s position and responsibility within our companyCompany and performance in that position, the importance of the executive’s position to our business, and the compensation of other executive officers of ADTRANthe Company with comparable qualifications, experience and responsibilities. The Committee also generally takes into account its perceivedthe range of salaries of executive officers with comparable qualifications, experience and responsibilities at other companies with which we compete for executive talent.

For our sales executives, commissions are an important element of cash compensation because they tie the executive’s pay directly to his success in his area of responsibility. Our sales executives generally receive half of their cash compensation (not including annual VICC, if any) in salary and half in commissions, which is consistent with our historical practice and our understandingAt a meeting of the standard practice in the market for sales executives. TheCompensation Committee also reviews historical salary and commission information for each of the executive officers as part of its analysis in setting base salaries and commission structures. The Committee uses this information to review historical progression of each executive officer’s compensation and to identify variations in compensation levels among the executive officers.

Inheld on January 2015,20, 2023, the Compensation Committee reviewed the base salaries of our executive officers, taking into account the considerations described above. The Committee approved the following base salaries for the NEOs:

As discussed above, on December 1, 2023, the Compensation Committee authorized the following temporary reductions in base salary increasesfor the NEOs, which individuals had voluntarily agreed to prior to the Committee’s approval: a 50% reduction in base salary for Mr. Stanton and a 25% reduction in base salary for each of the named executive officers whichMr. Dopfer, Mr. Wilson and Dr. Glingener. Mr. Stanton’s and Mr. Wilson’s salary reductions are reflectedeffective from October 30, 2023 through July 31, 2024, and Mr. Dopfer’s and Dr. Glingener’s salary reductions are effective from November 1, 2023 through July 31, 2024. These temporary salary reductions were implemented in the following table:

Additionally, in November, 2015, Roger D. Shannon joined the Company as our Senior Vice President of Finance and Chief Financial Officer, replacing Mr. Matthews who resigned in March, 2015. In connection with Mr. Shannon’s hiring, the Committee approved an annual salary for Mr. ShannonBusiness Efficiency Program that was developed during the second half of $365,000. Mr. Matthews’ resignation became effective2023 as a result of ongoing uncertainty around the current macroeconomic environment and its impact on March 16, 2015, and Mr. Foliano served as Interim Chief Financial Officer until Mr. Shannon assumed that position.customer spending levels.

Annual Incentive Compensation.Short-Term Cash Incentives

2023 Bonus Program

We provide our executivesexecutive officers, including our NEOs, with the opportunity to earn annual VICCshort-term cash incentive compensation under our Variable Incentive Compensation Plan, whichbonus programs, including our VICC. The VICC program is designed to motivate and reward executives for their contribution to ADTRAN’sthe Company’s performance during the fiscal year. A significant portion of the total cash compensation that our executive officers couldare eligible to receive each year is paid through this program, and thus is dependent upon our corporate performance.

On January 20, 2023, the Compensation Committee established the VICC availableprogram for 2015 was2023. The Committee chose to base the VICC program for 2023 on two measures of the Company’s financial and operating performance in 2023 (collectively, the “Company Performance Measures”): the Company’s “Adjusted EBIT” (defined as the Company’s earnings before interest and tax, determined by a formula based on designated performance measures for total company operating income, total company revenue, Carrier Network performance, Enterprise Network performancethe Company’s audited financial results, and certain other subcategoriesadjusted to remove any restructuring expenses; acquisition-related expenses and amortization of revenue, as well as personal goal elements for some participants, as describedintangibles; stock-based compensation expense; the non-cash change in fair value of equity investments held in the narrative followingDeferred Compensation Plan; and any other non-GAAP exclusions approved by the Summary Compensation TableCommittee) and the Grants of Plan-Based Awards table. We use these performance measures for our annual incentive awardsCompany’s revenue. The Compensation Committee chose to utilize the Company Performance Measures in the 2023 VICC program because we consider them asthese measures to be the most appropriate drivers of stockholder value. Total company operating incomeIn 2022, the Committee based the bonus program on the Company’s adjusted gross margin performance in order to intensify management’s focus on gross margins, as the increased cost of goods due to the ongoing and total company revenue performance measures requiredsevere constraints in the supply chain was a growth ratesignificant detriment to the Company’s profits in recent years.

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The Compensation Committee established a target for each Company Performance Measure for the first quarter of 2023 at least 2.5% in that measure overits meeting on January 20, 2023 and then established a target for the prior year’s performancesecond quarter of 2023 at the Committee’s meeting on April 14, 2023. The Compensation Committee certified the level of achievement for officerseach of these two quarters at the Committee’s subsequent quarterly meeting. At the Compensation Committee’s meeting on July 14, 2023, the Committee determined it was appropriate to establish a target for each Company Performance Measure for the second half of 2023. In order to be eligible to receive any VICC. bonus amount for each of the first two quarters or the second half of 2023, the Company must have achieved in such time period a prescribed minimum threshold level for each Company Performance Measure.

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 – $1,400,000 (140%), Mr. Dopfer – $246,000 (60%), Mr. Wilson – $162,029 (40%), Dr. Glingener – $210,000 (60%), and Mr. Foliano – $360,110 (80%). Mr. Foliano forfeited his 2023 cash incentive award in connection with his retirement from the Company effective June 28, 2023.

The bonus awards for 2023 were based on the two Company Performance Measures described above:

Payouts for performance between the threshold and maximum levels were subject to non-linear interpolation. Failure to meet the minimum performance measures.threshold corresponding to a specific performance measure in a fiscal quarter (or half year) would have resulted in the participant not receiving any portion of the payout award related to such performance measure for the quarter (or half year). 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 hasbelieves that it is appropriate to establish a maximum payout that any participant could receive under the discretionbonus programs in order to decreaseavoid an excessive payout should Company results or individual performance significantly exceed expectations.

2023 Actual Bonus Program Results

As the performance thresholds for the 2023 bonus program were not achieved during either of the first two quarters of 2023 or the second half of 2023, none of the NEOs received a VICC payout under the plan even2023 bonus program.

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2023 Sales Incentive Arrangement for Chief Revenue Officer

The Company has in place a sales incentive program for certain of its employees whose focus is on sales. Mr. Wilson, our Chief Revenue Officer, began participating in this program in 2020. The Compensation Committee believes that sales incentives should be an important element of Mr. Wilson’s cash compensation, as they tie a portion of his pay directly to his success in his area of responsibility. As such, he receives a portion of his cash compensation in sales incentives, which is consistent with our historical practice and our understanding of the standard practice in the market for sales-oriented executives. The Compensation Committee approved a target sales incentive for Mr. Wilson in 2023 of $81,014 based on input from the CEO, which target is a percentage of sales revenue in 2023. The Compensation Committee and CEO set the gross shipment performance target at a level that it believes was reasonably difficult to achieve given the business environment at the time the target was established. The sales incentive arrangement further allows Mr. Wilson to earn up to 180% of his target amount if certain gross direct shipments exceed the defined performance measurestarget. If Mr. Wilson’s achievement exceeds 180% of the performance target amount for the year, these payments are met, butwithheld until the Committee does not havenext year and paid out in equal quarterly installments. 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 under the plan to increasedetermine that a VICC payout above“windfall” has occurred and decrease the amount determined pursuantpaid to the established VICC formula.

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For 2015, the Company did not meet the performance measures established for the 2015 program under the Variable Incentive Compensation Plan. Consequently, our executives did not earn any bonuses for 2015 performance under that plan.

Long-Term Incentive Awards. We compensateAwards

Historically, we have compensated our executive officers, in partincluding our NEOs, with annual grants of stock optionequity awards granted under ourthe ADTRAN Holdings, Inc. 2020 Employee Stock Incentive Plan (as amended and restated, the “2020 Employee Plan”), which replaced the ADTRAN Holdings, Inc. 2015 Employee Stock Incentive Plan which(the “2015 Employee Plan”) upon its approval by the stockholders at the 2020 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—2020 Employee Stock Incentive Plan” beginning on page 54 for a description of our 2020 Employee Plan and “Proposal 2: Approval of the ADTRAN Holdings, Inc. 2024 Employee Stock Incentive Plan” beginning on page 77 for a description of the proposed 2024 Employee Stock Incentive Plan. The purpose of our incentive plans is described in the narrative following the Summary Compensation Table and the Grantsto provide equity as a component of Plan-Based Awards table. We grant stock options every year because these awards are consistent withexecutive compensation to ensure competitiveness of our compensation goalsprogram, 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 aligning executives’ interests with those of our stockholdersthe executives during the vesting period since, in most circumstances, the long term, and because these awards are a standard form of compensation amongwill be forfeited if the companies with which we compete for executive talent. executive’s employment terminates before the award vests.

The Compensation Committee believestypically grants 50% of the Annual Equity Awards in the form of time-based RSUs that stock option awardsvest ratably over four years and 50% in the form of market-based PSUs that the NEOs are an especially valuable tool in linking the personal interests of executiveseligible to those of our stockholders, because executives’ compensation under these awards is directly linked to our stock price. These awards give executive officers a significant, long-term interest in ADTRAN’s success. In addition, they can provide beneficial tax treatment that executives value due to the fact that we have typically granted incentive stock options to our executives to the maximum extent permitted under the tax laws. Moreover, the vesting component of our stock option awards provides a valuable retention tool, and retention is a significant consideration in making these awards.

As discussed above under “Overview and Philosophy,” in 2008 the Compensation Committee,earn based on discussions with the Chief Executive Officer and after considering information received from Towers Watson and other industry surveys and databases, determined to allow for performance-based restricted stock units, referred to as “performance shares,” in addition to other equity-based awards for the Chief Executive Officer and the Senior Vice Presidents. The Committee chose this form of award to further implement our executive compensation goals of better aligning the interests of these executives, who can most directly impact our overall financialCompany performance with the interests of our stockholders and of our Company by making the awards dependent on corporate performance, and allocated a portion of the long-term incentive awards for these executive officers accordingly. The number of performance shares earned by the executive officers is based on our relative total shareholder return, or “TSR,” against a peer group over a three-year performance period. For 2015,Additionally, in 2023, the Compensation Committee selected ascontinued to grant performance-based PSUs to the NEOs that are eligible to be earned based on a peer group all companies infinancial performance measure over a three-year performance period pursuant to the NASDAQ Telecommunications Index. The2023 Long-Term Financial Plan. Finally, the Committee chose this indexgranted (i) one-time “integration awards” to the NEOs that are eligible to be earned based on the fact that it containsachievement of cost savings targets related to the Business Combination over a significant number of companiestwo-year performance period and(ii) one-time stock options to Mr. Wilson in connection with his temporary salary reduction approved by the Committee on December 1, 2023.

Below is a broad sample of our industry.

We believe that TSR is an important tool in aligning our business goals with our executive compensation program, and ADTRAN is committed to delivering strong total shareholder return. Our 2015 TSR was negatively impacted by a significant decline in the valuesummary of the euro comparedAnnual Equity Awards granted to certain of the NEOs on January 20, 2023 (except as noted below) and the performance-based PSUs pursuant to the U.S. dollar, and2023 Long-Term Financial Plan granted to certain of the cancellation of a projectNEOs on March 1, 2023 (except as noted below), with a major tier 1 service provider indetails regarding such awards following the U.S. Although U.S. sales growth in 2015 was 10%, the resulting revenue and operating income we believe negatively impacted our resulting TSR. During the course of 2015, the company has taken steps to reduce operating expense by consolidating facilities and believes this, in combination with market share gains and improving environment should lead to better TSR performance in the future. To this end, we believe our executive compensation programs provide significant incentive to our management to work towards long-term TSR growth.

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Shares earned are distributed at the end of the three-year performance period. Under the award agreements, a portion of the granted performance shares also vest and become deliverable upon the death or disability of a recipient or upon a change of control of ADTRAN, as discussed in more detail below under the heading “Potential Payments Upon Termination or Change of Control.” The recipients of the performance shares under the award agreements receive dividend credits based on the shares of common stock underlying the performance shares. The dividend credits are paid in cash upon vesting of those shares under the applicable awards.

The 2012 grant of performance shares vested on November 3, 2015 and the Compensation Committee certified in November 2015 that the TSR relative to its peer group over the performance period was 40.1%. As a result, the recipients earned 75.26% of the performance shares originally granted and payment, in cash, of the dividend credits accrued on such earned performance shares.

Our long-term equity incentive awards are timed to occur in the latter part of each year, to coincide with an open trading window under our insider trading policy. In November 2015, the Compensation Committee approved stock option awards to our executive officers that vest over a four year period, with 25% vesting on each anniversary of the grant date. In addition, in November 2015, the Committee approved performance share awards to the Chief Executive Officer and the Senior Vice Presidents, as discussed above, including Roger D. Shannon, upon his appointment as Senior Vice President of Finance and Chief Financial Officer of the Company in November 2015. The total awards to the named executive officers in 2015 were as follows, and are described in the narrative below the Grants of Plan-Based Awards table:

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InCommittee’s process for determining the amountamounts of thesethe incentive equity awards begins with a consideration of the Compensationoverall dollar level of value that the Committee began by deciding on an overall pool amount for the company,determines is appropriate, taking into account the estimated expense to usthe Company of the awards and the earnings per share impact of that expense. WeThe Committee typically establishestablishes an internal target for the aggregate expense from company-wide optionCompany-wide equity awards, and performance shares, 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. TheThis 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 1,181,488 stock options583,310 RSUs and 34,247 performance sharesPSUs to be granted to all participants in the 2020 Employee Plan for the 2015 annual grant, as compared2023 Annual Equity Awards. The 218,810 RSUs and PSUs granted to a pool of up to 1,197,595 stock options and 29,947 performance shares for the 2014 annual grant.NEOs in 2023 are included in this total. The Compensation Committee allocated the pool of optionsRSUs and performance sharesPSUs among the different functions throughout the company,Company based on the importance and performance of the function and considerations such as retention and competitive compensation levels. The Compensation Committee then set each executive’s individual award fromalso considered the amount allocatedrecommendations of our CEO with respect to the functionawards to other executives and employees, as well as individual and Company performance during 2021 and 2022.

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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. Under the award agreements and Mr. Stanton’s Employment Agreement, a portion of the granted market-based PSUs also vest and become issuable upon the termination of a recipient’s employment or upon a change of control of the Company, as discussed in which he serves,more detail below under the heading “Potential Payments Upon Termination or Change of Control.” 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 recommendationshares of our Chief Executive Officer (other than with respect to his own award) with input from our Chief Financial Officer. In determiningcommon stock underlying the amountmarket-based PSUs. The dividend credits are vested, earned and distributed in cash upon issuance of the optionsshares pursuant to the earned market-based PSUs. Recipients may choose to defer shares issued pursuant to earned PSUs under the Deferred Compensation Plan instead of receiving the shares at the time they are entitled to distribution of the shares.

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Integration Awards

On March 1, 2023, the Compensation Committee established an “Integration Bonus Plan” consisting of a combination of performance-based PSUs and performance shares forcash bonus award amounts (together with the named executive officers,PSUs, the Committee considered“Integration Awards”). Under the conclusions of its 2015 compensation review described above.

The Company has not historically included a performance measure as a component of vesting of stock options for executive officers because we believe that performanceIntegration Bonus Plan, certain key employees of the Company, including the NEOs (other than Mr. Foliano as described below), are eligible to earn the Integration Awards over a performance period beginning on the grant date (for Messrs. Stanton and Wilson, March 1, 2023, and for Mr. Dopfer and Dr. Glingener, May 24, 2023) and ending on December 31, 2024, based on the achievement of cost savings targets related to the Business Combination during such period. The Compensation Committee chose the performance measure of “Company Synergy Achievement” in order to incentivize the participants to drive cost savings and expected synergies following the closing of the Business Combination, and it approved a target level of synergies against which the Company’s non-GAAP expenses will be measured. For purposes of measuring performance, the Company’s GAAP expenses will be adjusted for restructuring expenses; acquisition-related expenses, amortizations and adjustments; stock-based compensation expense; amortization of actuarial pension losses and the impact of equity market changes on deferred compensation expenses; non-operating income; and any other exclusions adopted by the Company. The Compensation Committee set the synergies performance target at a level that it believes was reasonably difficult to achieve given the business environment at the time the target was established.

If the Company Synergy Achievement over the performance period reaches the performance levels noted below, the participants will be entitled to a corresponding number of shares of the Company’s common stock under the PSUs:

If the threshold level of Company Synergy Achievement is reached, the participants are also eligible to receive a cash award up to 66% of their base salary (as of the grant date) based on the percentage of individual objectives related to cost savings achieved by each participant, as determined by the Compensation Committee. If the target level of Company Synergy Achievement is achieved and thatall of the option itself provides significant incentiveindividual objectives are achieved, the participants will earn a maximum amount under the Integration Bonus Plan equal to each employee who receives an option (including our executives)132% of their base salary, as reflected below:

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