Amentum Holdings, Inc. (Form: 4, Received: 10/04/2024 17:52:15)

FORM 4 ☐ Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). ☐ Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^* Arnette Stephen A	2. Issuer Name and Ticker or Trading Symbol Amentum Holdings, Inc. [ AMTM ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Operating Officer
(Last) (First) (Middle) C/O AMENTUM HOLDINGS, INC., 4800 WESTFIELDS BOULEVARD, SUITE 400	3. Date of Earliest Transaction (MM/DD/YYYY) 10/2/2024
(Street) CHANTILLY, VA 20151	4. If Amendment, Date Original Filed (MM/DD/YYYY)	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. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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)
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)			11. Nature of Indirect Beneficial Ownership (Instr. 4)
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		521		⁽²⁾	⁽²⁾	Common Stock	521	$0	521	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		1,178		⁽³⁾	⁽³⁾	Common Stock	1,178	$0	1,178	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		4,038		⁽⁴⁾	⁽⁴⁾	Common Stock	4,038	$0	4,038	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		10,106		⁽⁵⁾	⁽⁵⁾	Common Stock	10,106	$0	10,106	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		17,273		⁽⁶⁾	⁽⁶⁾	Common Stock	17,273	$0	17,273	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		3,681		⁽⁷⁾	⁽⁷⁾	Common Stock	3,681	$0	3,681	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		4,596		⁽⁷⁾	⁽⁷⁾	Common Stock	4,596	$0	4,596	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		10,984		⁽⁸⁾	⁽⁸⁾	Common Stock	10,984	$0	10,984	D
Restricted Stock Units ⁽¹⁾	⁽¹⁾	10/2/2024		A		10,395		⁽⁸⁾	⁽⁸⁾	Common Stock	10,395	$0	10,395	D

Explanation of Responses:
(1)	These restricted stock units ("RSUs") were originally granted by Jacobs Solutions Inc. ("Jacobs") and, pursuant to the terms of the Employee Matters Agreement, dated as of November 20, 2023, by and among Jacobs, the Issuer and Amentum Parent Holdings LLC, as amended from time to time, were converted into RSUs with respect to Issuer common stock with adjustments made to the number of shares subject to the award in order to preserve the award's value. The conversion ratio was determined based on the closing price per share of Jacobs common stock on September 27, 2024 divided by the average of the volume-weighted average prices of the Issuer's common stock on the New York Stock Exchange for the period beginning on September 30, 2024 and ending on October 2, 2024.
(2)	This award will vest in full on March 4, 2025, subject to the reporting person's continued service through such date.
(3)	This award will vest in full on November 17, 2025, subject to the reporting person's continued service through such date.
(4)	This award will vest with respect to 1,230 RSUs on March 2, 2025 and 2,808 RSUs on March 2, 2026, subject to the reporting person's continued service through the applicable date.
(5)	This award will vest in two equal installments on November 16, 2025 and November 16, 2026, subject to the reporting person's continued service through the applicable date.
(6)	This award will vest in three equal installments on November 15, 2025, November 15, 2026 and November 15, 2027, subject to the reporting person's continued service through such date.
(7)	This award was originally granted by Jacobs subject to a performance condition, which was deemed satisfied based on actual performance prior to the conversion, and as a result is now solely subject to time-vesting conditions. This award will vest in full on November 16, 2025, subject to the reporting person's continued service through such date.
(8)	This award was originally granted by Jacobs subject to a performance condition, which was deemed satisfied based on actual performance prior to the conversion, and as a result is now solely subject to time-vesting conditions. This award will vest in full on November 15, 2026, subject to the reporting person's continued service through such date.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Arnette Stephen A C/O AMENTUM HOLDINGS, INC. 4800 WESTFIELDS BOULEVARD, SUITE 400 CHANTILLY, VA 20151			Chief Operating Officer

Signatures
/s/ Paul W. Cobb, Jr. Attorney-in-fact		10/4/2024
^**Signature of Reporting Person		Date

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