Director Kevin Holleran Receives 876 Restricted Stock Units in Armstrong World Industries

This Form 4 filing reports that Kevin Holleran, a director of Armstrong World Industries Inc., received 876 restricted stock units on June 12, 2026, as part of the company's nonemployee Director Compensation Program. The units were granted under the 2016 Directors Stock Unit Plan and represent the equity portion of Holleran's annual retainer for Board service. The grant date fair value was calculated using the closing stock price of $154.21 per share on June 12, 2026. The restricted stock units vest on the earlier of: (1) the date of the next annual shareholders meeting following the grant, (2) the director's death or total and permanent disability, or (3) a Change in Control event. Following this transaction, Holleran holds a total of 1,311 units, including both vested and unvested units. Vested units become acquirable by the director either at the vesting date or upon termination of service.