ADTRAN Holdings, Inc. (NASDAQ:ADTN) ("ADTRAN Holdings" or the "Company") today announced that its previously postponed 2025 annual meeting of stockholders (the "Annual Meeting") has been rescheduled for Thursday, July 24, 2025.

The Company intends to file a revised definitive proxy statement (the "Revised Proxy Statement") with the Securities and Exchange Commission ("SEC") to reflect, among other things, the rescheduled meeting date for the Annual Meeting and the new record date for the Annual Meeting. The Company will deliver a new notice of the Annual Meeting and proxy card to all stockholders entitled to vote as of the new record date for the Annual Meeting.

About Adtran

ADTRAN Holdings, Inc. (NASDAQ:ADTN) is the parent company of Adtran, Inc., a leading global provider of open, disaggregated networking and communications solutions that enable voice, data, video and internet communications across any network infrastructure. From the cloud edge to the subscriber edge, Adtran empowers communications service providers around the world to manage and scale services that connect people, places and things. Adtran solutions are used by service providers, private enterprises, government organizations and millions of individual users worldwide. ADTRAN Holdings, Inc. is also the majority shareholder of Adtran Networks SE, formerly ADVA Optical Networking SE. Find more at Adtran, LinkedIn and X.

Additional Information Regarding the Annual Meeting of Stockholders and Where to Find It

On March 31, 2025, the Company filed a definitive proxy statement containing a form of proxy card with the SEC in connection with its solicitation of proxies for the Annual Meeting (the "Original Proxy Statement"), and it anticipates that it will prepare and file a revised version of the Original Proxy Statement (the "Revised Proxy Statement") and mail the Revised Proxy Statement to its stockholders of record as of the new May 29, 2025 record date for the Annual Meeting. Any votes previously submitted by the Company's stockholders in connection with the Annual Meeting will not be counted and previous proxies submitted will be disregarded and, therefore, all stockholders will need to resubmit their votes after the Revised Proxy Statement has been filed and delivered to stockholders as of the new record date, even if they have previously voted. THE COMPANY'S STOCKHOLDERS ARE STRONGLY ENCOURAGED TO READ THE REVISED PROXY STATEMENT (AND ANY AMENDMENTS AND SUPPLEMENTS THERETO) AND ACCOMPANYING PROXY CARD AS THEY WILL CONTAIN IMPORTANT INFORMATION. Stockholders may obtain the Original Proxy Statement, the Revised Proxy Statement and any amendments or supplements thereto and other documents as and when filed by the Company with the SEC without charge from the SEC's website at www.sec.gov.

Participants in the Solicitation

The Company and its directors, executive officers and certain employees and other persons may be deemed to be participants in the solicitation of proxies from the Company's stockholders in connection with the business to be conducted at the Annual Meeting. See Amendment No. 1 to the Company's Annual Report on Form 10-K for the year ended December 31, 2024, which was filed with the SEC on May 20, 2025, and the Revised Proxy Statement, to be filed with the SEC, for information regarding the names and interests of the Company's directors and executive officers.

Forward-Looking Statements

Statements contained in this press release which are not historical facts, such as those relating to the timing for holding the Annual Meeting, the Company's intent to file the Revised Proxy Statement, and related matters are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements can also generally be identified by the use of words such as "believe," "expect," "intend," "estimate," "anticipate," "will," "may," "could" and similar expressions. In addition, ADTRAN Holdings, through its senior management, may from time to time make forward-looking public statements concerning the matters described herein. All such projections and other forward-looking information speak only as of the date hereof, and ADTRAN Holdings undertakes no duty to publicly update or revise such forward-looking information, whether as a result of new information, future events, or otherwise, except to the extent as may be required by law. All such forward-looking statements are necessarily estimates and reflect management's best judgment based upon current information. Actual events or results may differ materially from those anticipated in these forward-looking statements as a result of a variety of factors. While it is impossible to identify all such factors, factors which have caused and may in the future cause actual events or results to differ materially from those estimated by ADTRAN Holdings include, but are not limited to the risk of potential delays in the finalization of the Revised Proxy Statement and the risks set forth in our public filings made with the SEC, including our most recent Annual Report on Form 10-K for the year ended December 31, 2024, as amended, our Form 10-Q for the quarterly period ended March 31, 2025, and other documents on file with the SEC.

Published by

ADTRAN Holdings, Inc.

www.adtran.com

View source version on businesswire.com: https://www.businesswire.com/news/home/20250527326747/en/

For media

Gareth Spence

+44 1904 699 358

public.relations@adtran.com

For investors

Peter Schuman, IRC

+1 256 963 6305

investor.relations@adtran.com

ADTRAN Holdings, Inc. announces date of 2025 annual meeting of stockholders