Exhibit 10.4
ADTRAN HOLDINGS, INC. RESTRICTED STOCK UNIT AGREEMENT
This Restricted Stock Unit Agreement (this “Agreement”) sets forth the specified terms of ADTRAN Holdings, Inc.’s grant of the number of Restricted Stock Units (“RSU”) as is set forth in the Morgan Stanley StockPlan Connect (the “Portal”) to the applicable grantee named in the Portal (the “Participant”) pursuant to the ADTRAN Holdings, Inc. 2024 Employee Stock Incentive Plan (the “Plan”) as of the date of grant set forth in the Portal. All capitalized terms used but not defined herein shall have the meanings ascribed to such terms in the Plan.
Anniversary of the date of grant: | Vested percentage: |
One-year anniversary | 25% |
Two-year anniversary | 25% |
Three-year anniversary | 25% |
Four-year anniversary | 25% |
Under the above schedule, before the one-year anniversary, no part of the Award is vested or nonforteitable.
(1) the Participant’s death or (2) the Participant’s Separation from Service due to Disability, all outstanding unvested RSUs shall immediately vest. One share of the Company’s Common Stock shall be issued to the Participant for every vested RSU as soon as administratively practicable following the acceleration event.
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Participant Name:
Beneficiary Name:
Address:
Relationship:
□Check this box to apply the above beneficiary designation to all prior grants.
To complete this beneficiary designation, this Agreement should be printed out, the information above should then be completed, and the Agreement should then be emailed to Human Resources at [***]. The Participant may modify this beneficiary designation by submitting the change in writing to the Company. Beneficiary designations are not effective until received by the Company. If no beneficiary is designated, then except as may be provided in the Plan, any benefits due hereunder following the death of the Participant will be paid to the Participant’s estate.
If there are any questions regarding this Agreement or the RSUs, please refer to the Plan or contact Human Resources at.
ADTRAN HOLDINGS, INC.

Thomas R. Stanton Chief Executive Officer
PARTICIPANT
Name:
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