Item 6. Exhibits

Exhibits:


4.1			Twenty-Fourth Supplemental Indenture, dated as of May 6, 2026, between the Company and The Bank of New York Mellon (filed as Exhibit 4.2 to the Company’s current report on Form 8-K (Date of Report: May 6, 2026) and incorporated herein by reference) (Commission File Number 001-12215)

4.2			Form of the Company’s 5.000% Senior Note due 2036 (filed as Exhibit 4.3 to the Company’s current report on Form 8-K (Date of Report: May 6, 2026) and incorporated herein by reference) (Commission File Number 001-12215)



22			Subsidiary Guarantors of Securities

31.1			Rule 13a-14(a) Certification of Chief Executive Officer

31.2			Rule 13a-14(a) Certification of Chief Financial Officer

32.1			Section 1350 Certification of Chief Executive Officer

32.2			Section 1350 Certification of Chief Financial Officer

101.INS			Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document

101.SCH			Inline XBRL Taxonomy Extension Schema Document - dgx-20260630.xsd

101.CAL			Inline XBRL Taxonomy Extension Calculation Linkbase Document - dgx-20260630_cal.xml

101.DEF			Inline XBRL Taxonomy Extension Definition Linkbase Document - dgx-20260630_def.xml

101.LAB			Inline XBRL Taxonomy Extension Label Linkbase Document - dgx-20260630_lab.xml

101.PRE			Inline XBRL Taxonomy Extension Presentation Linkbase Document - dgx-20260630_pre.xml

104			Cover Page Interactive Data File (formatted in Inline XBRL and contained in Exhibit 101)

Signatures

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

July 23, 2026

Quest Diagnostics Incorporated


By			/s/ James E. Davis
			James E. Davis
			Chairman, Chief Executive Officer
			and President


By			/s/ Sam A. Samad
			Sam A. Samad
			Executive Vice President and
			Chief Financial Officer

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