DGX: Financial results

Item 2.02. Results of Operations and Financial Condition On October 22, 2026, Quest Diagnostics Incorporated (the "Company") issued a press release announcing, among other things, its results for the quarter ended September 30, 2026. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated by reference herein. Item 9.01. Financial Statements and Exhibits d. Exhibit 99.1 Press release of Quest Diagnostics Incorporated dated October 22, 2026, announcing, among other things, its results for the quarter ended September 30, 2026. 104 The cover page from this current report on Form 8-K, formatted in Inline XBRL. Signature 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 hereunto duly authorized. October 22, 2026 QUEST DIAGNOSTICS INCORPORATED By: /s/ Sean D. Mersten Sean D. Mersten Vice President and Corporate Secretary