X0609 4 2026-10-21 0 0001022079 QUEST DIAGNOSTICS INC DGX 0001805909 Lassiter Wright III false 500 PLAZA DRIVE C/O QUEST DIAGNOSTICS SECAUCUS NJ 07094 1 0 0 0 0 Common Stock 2026-10-21 5 L 0 E 6 235.959 A 10329 D Reflects shares that were acquired pursuant to a dividend reinvestment plan administered by the reporting person's broker and eligible for deferred reporting on Form 5 under Rule 16a-6. The reporting person has chosen to report such transaction early on this Form 4. Sean D. Mersten, Attorney in Fact for Wright L. Lassiter, III 2026-10-23