Sec Form 4 Filing - SHEAHAN DENIS K @ Eastern Bankshares, Inc. - 2025-03-03

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person SHEAHAN DENIS K 2. Issuer Name and Ticker or Trading Symbol Eastern Bankshares, Inc. [ EBC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Executive Officer (Last) (First) (Middle) 125 HIGH STREET 3. Date of Earliest Transaction (MM/DD/YY) 03/03/2025 (Street) BOSTON, MA02110 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 246,337 I By Revocable Trust Common Stock 3,461 I By ESOP

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Restricted Stock Units ( 1 ) ( 2 ) ( 3 ) ( 3 ) Common stock 3,232 3,232 D Restricted Stock Units ( 1 ) ( 2 ) ( 4 ) ( 4 ) Common stock 11,241 11,241 D Restricted Stock Units ( 1 ) ( 2 ) ( 5 ) ( 5 ) Common stock 34,544 34,544 D Restricted Stock Units ( 1 ) ( 2 ) ( 6 ) ( 6 ) Common stock 33,721 33,721 D Restricted Stock Units ( 1 ) ( 2 ) ( 7 ) ( 7 ) Common stock 42,221 42,221 D Restricted Stock Units ( 8 ) ( 9 ) ( 9 ) Common stock 25,821 25,821 D Restricted Stock Units ( 8 ) 03/03/2025 A 154,088 ( 10 ) ( 10 ) Common stock 154,088 $ 0 154,088 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SHEAHAN DENIS K 125 HIGH STREET BOSTON, MA02110 X Chief Executive Officer Signatures /s/ Kathleen R. Henry, by Power of Attorney 03/05/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Eastern Bankshares, Inc. (the "Company") issued these time-based restricted stock units ("RSUs") as of July 12, 2024, when the Company completed a merger with Cambridge Bancorp ("Cambridge"). Pursuant to the terms of the Agreement and Plan of Merger, dated September 19, 2023, Cambridge RSUs and performance-based restricted stock units ("PRSUs") were assumed and converted to Company RSUs at an exchange ratio of 4.956 Company units for each Cambridge unit. ( 2 )Restricted stock units convert into common stock on a one-for-one basis. ( 3 )This award for 3,232 Company RSUs replaced an award of Cambridge RSUs granted to the reporting person on February 15, 2021, that vested in three equal annual installments beginning one year after the grant date. The reporting person elected to defer receipt of common stock issuable upon the vesting of these RSUs. ( 4 )This award for 11,241 Company RSUs replaced an award of Cambridge RSUs granted to the reporting person on February 15, 2022, that provided for vesting in three equal annual installments beginning one year after the grant date. The final tranche of this Company RSU award vested on February 15, 2025. The reporting person elected to defer receipt of common stock issuable upon vesting except for shares withheld for tax obligations. ( 5 )This award for 34,544 Company RSUs replaced an award of Cambridge RSUs granted to the reporting person on April 28, 2023, that provided for vesting in three equal annual installments beginning one year after the grant date. Subject to continued service, the remaining tranches will vest on April 28 of 2025 and 2026, respectively. The reporting person elected to defer receipt of common stock issuable upon vesting except for shares withheld for tax obligations. ( 6 )This award for 33,721 Company RSUs replaced an award of Cambridge PRSUs granted to the reporting person on February 15, 2022. The Company RSU award provided for cliff vesting on December 31, 2024. The reporting person elected to defer receipt of common stock issuable upon vesting except for shares withheld for tax obligations. ( 7 )This award for 42,221 Company RSUs replaced an award of Cambridge PRSUs that Cambridge granted to the reporting person on April 28, 2023. Subject to continued service, the Company RSU award provides for cliff vesting on December 31, 2025. The reporting person elected to defer receipt of common stock issuable upon vesting except for shares withheld for tax obligations. ( 8 )Each restricted stock unit represents a contingent right to receive one share of Company common stock on the applicable vesting date. ( 9 )On September 3, 2024, the reporting person was granted 25,821 restricted stock units that vest in three equal annual installments beginning September 3, 2025, subject to continued service. Vested shares will be issued to the reporting person as soon as practicable after the vesting date. ( 10 )On March 3, 2025, the reporting person was granted 154,088 restricted stock units of which 24,365 vest in three equal annual installments and 129,723 vest in five equal annual installments beginning March 1, 2026, subject to continued service. Vested shares will be issued to the reporting person as soon as practicable after the vesting date.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.