X0609 4 2026-08-28 0 0001022079 QUEST DIAGNOSTICS INC DGX 0001222679 PREVOZNIK MICHAEL E false 500 PLAZA DRIVE SECAUCUS NJ 07094 0 1 0 0 SVP & General Counsel 1 Common Stock 2026-08-28 4 M 0 22677 112.17 A 60234 D Common Stock 2026-08-28 4 S 0 16010 242.8755 D 44224 D Common Stock 2026-08-28 4 S 0 6237 243.6275 D 37987 D Common Stock 2026-08-28 4 S 0 430 244.5148 D 37557 D Common Stock 2026-08-28 5 G 0 E 1000 0 D 36557 D Common Stock 5780 I 401(k)/SDCP Non-Qualifed Stock Option (right to buy) 112.17 2026-08-28 4 M 0 22677 112.17 D 2030-02-18 Common Stock 22677 0 D This exercise and sale reported were effected pursuant to a Rule 10b5-1 sales plan adopted by the reporting person. This transaction was executed in multiple trades at prices ranging from $242.270 to $243.269. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. This transaction was executed in multiple trades at prices ranging from $243.270 to $244.225. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. This transaction was executed in multiple trades at prices ranging from $244.280 to $245.247. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. On August 28, 2026, the reporting person made a charitable gift of 1,000 shares, a transaction eligible for deferred reporting on Form 5. The reporting person has chosen to report such transaction early on this Form 4. These underlying shares were acquired on a periodic basis by the trustee of the Company's tax qualified Profit Sharing (401(k)) and/or Supplemental Deferred Compensation Plan. The information was obtained from the plan administrator as of a current date. The number of shares is based on the account balance of the Company stock fund under each Plan (which includes some money market instruments) divided by the market price of the Company's stock as of that date. The options vested in three equal annual installments beginning on the first annual anniversary of the grant date. Sean D. Mersten, Attorney in Fact for Michael E. Prevoznik 2026-08-31