Sec Form 5 Filing - LALLY JAMES BRIAN @ ENTERPRISE FINANCIAL SERVICES CORP - 2023-12-31

FORM 5 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

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1. Name and Address of Reporting Person LALLY JAMES BRIAN 2. Issuer Name and Ticker or Trading Symbol ENTERPRISE FINANCIAL SERVICES CORP [ EFSC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) CEO (Last) (First) (Middle) 150 N. MERAMEC 3. Date of Earliest Transaction (MM/DD/YY) 12/31/2023 (Street) CLAYTON, MO63105 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 73,237 D Common Stock 18,028 I 401 (K) Plan ( 1 ) Common Stock 4,107 D ( 2 )

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 Non Qualified Stock Option (Right to Buy) $ 43.81 ( 3 ) 02/25/2031 Common Stock 17,637 17,637 D Non Qualified Stock Option (Right to Buy) $ 54.46 ( 4 ) 02/28/2033 Common Stock 20,438 20,438 D Non Qualified Stock Option (Right to Buy) $ 48.34 ( 5 ) 02/24/2032 Common Stock 20,325 20,325 D Restricted Share Units ( 6 ) ( 7 ) ( 7 ) Common Stock 3,345 3,345 D Restricted Share Units ( 6 ) ( 8 ) ( 8 ) Common Stock 3,592 3,592 D Restricted Share Units ( 6 ) ( 9 ) ( 9 ) Common Stock 4,176 4,176 D Restricted Share Units ( 6 ) ( 10 ) ( 10 ) Common Stock 23,947 23,947 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other LALLY JAMES BRIAN 150 N. MERAMEC CLAYTON, MO63105 X CEO Signatures /s/James Brian Lally 01/19/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These securities are represented by units held in a unitized stock fund through the Company's 401(k) Plan. The unitized stock fund consists of cash and common stock in amounts that vary from time to time. The Reporting Person has 35,183 units in the 401(k) Plan, which units consisted of 17,203 shares of common stock. ( 2 )These shares are held jointly with spouse. ( 3 )This option becomes exercisable after a three year period on 2/25/24. ( 4 )The option becomes exercisable after a three year period on 2/28/26. ( 5 )This option becomes exercisable after a three year period on 2/24/25. ( 6 )The RSU's were granted pursuant to the Company's 2018 Stock Incentive Plan. Each RSU represents the right to receive one share of Common Stock, subject to adjustment as provided in the Grant Agreement. ( 7 )The RSU's vest 100% in the first quarter of 2024, subject to continued employment by the reporting person. ( 8 )The RSU's vest 100% in the first quarter of 2025, subject to continued employment by the reporting person. ( 9 )The RSU vest 100% in the first quarter of 2026, subject to continued employment by the reporting person. ( 10 )The RSUs vest over six years in one-third installments on each of February 24, 2024, February 24, 2026, and February 24, 2028. Vesting is subject to continued employment of the reporting person. On each vesting date, for each RSU vesting on such date, the reporting person will receive one share of Common Stock.

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).

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