[Form 4] QUEST DIAGNOSTICS INC Insider Trading Activity

Rhea-AI Filing Summary

Quest Diagnostics (DGX) director Gary M. Pfeiffer reported a sale of common stock. On 10/22/2025, he sold 1,482 shares at $182.40 per share, and reported 29,431 shares beneficially owned directly after the transaction.

The filing also records an intra-plan transfer on 10/23/2025 within the company’s Amended and Restated Deferred Compensation Plan for Directors. 4,413.284 phantom common stock units—payable in cash and representing an equivalent number of shares—were transferred from the company stock fund to another investment option at a listed price of $190.58.

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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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 for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

PFEIFFER GARY M

(Last) (First) (Middle)

500 PLAZA DRIVE

(Street)

SECAUCUS NJ 07094

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
QUEST DIAGNOSTICS INC [ DGX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
10/22/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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	10/22/2025		S		1,482	D	$182.4	29,431	D

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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		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: 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
Phantom Stock	(1)	10/23/2025		I			4,413.284	(1)	(1)	Common Stock	4,413.284(2)	$190.58	0	D

Explanation of Responses:

1. This transaction constitutes an intra-plan transfer in the Quest Diagnostics Incorporated Amended and Restated Deferred Compensation Plan for Directors from the company stock fund to another investment option. The phantom common stock units were payable in cash and represented a like number of shares of the company's common stock.

2. The amount includes shares acquired via dividend reinvestment since the date of reporting person's last filing on Form 4 pursuant to the Amended and Restated Deferred Compensation Plan for Directors.

Remarks:

	Sean D. Mersten, Attorney in Fact for Gary M. Pfeiffer	10/24/2025
	** Signature of Reporting Person	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.

FAQ

What insider transaction did DGX report on Form 4?

Director Gary M. Pfeiffer sold 1,482 common shares at $182.40 on 10/22/2025.

How many Quest Diagnostics (DGX) shares does the director own after the sale?

He reported 29,431 shares beneficially owned directly after the transaction.

What was disclosed about DGX phantom stock units?

On 10/23/2025, 4,413.284 phantom stock units—payable in cash—were transferred within the directors’ deferred compensation plan.

What price is associated with the phantom unit entry?

The filing lists a price of $190.58 for the phantom stock entry.

Was the DGX transaction under a Rule 10b5-1 plan?

The excerpt includes the 10b5-1 checkbox instruction, but it does not show it as selected.

Who signed the filing?

It was signed by Sean D. Mersten, Attorney-in-Fact for Gary M. Pfeiffer, on 10/24/2025.