X0609 4 2026-10-06 0 0001673985 AdvanSix Inc. ASIX 0001338883 Williams Patrick false 300 KIMBALL DRIVE, SUITE 101 PARSIPPANY NJ 07054 1 0 0 0 0 Common Stock, par value $0.01 2026-10-06 4 A 0 785 16.70 A 44219 D Represents the allocation of deferred compensation to the reporting person's deferred stock unit fund account under the AdvanSix Inc. Deferred Compensation Plan. Each unit allocated under the stock unit fund represents the economic equivalent of one share of common stock. Units are paid out in shares of AdvanSix Inc. common stock upon distribution. /s/ Achilles B. Kintiroglou for Patrick Williams 2026-10-08