X0306 4 2017-01-17 0000007431 ARMSTRONG WORLD INDUSTRIES INC AWI 0001671163 MacNeal Brian L C/O ARMSTRONG WORLD INDUSTRIES, INC. 2500 COLUMBIA AVENUE, P.O. BOX 3001 LANCASTER PA 17603 1 CFO Common Stock 2017-01-17 4 M 0 573 0 A 1167 D Common Stock 2017-01-17 4 F 0 211 41.80 D 956 D Restricted Stock Units 2017-01-17 4 M 0 573 0 D Common Stock 573 0 D Reflects the conversion of previously granted restricted stock units into shares at Issuer's common stock in connection with the settlement of the restricted stock units. Each restricted stock unit represents a contingent right to receive one share of Issuer's common stock. Represents the number of shares withheld by the Issuer to satisfy the Reporting Person's tax obligations upon the settlement of restricted stock units granted to the Reporting Person under the Issuer's 2011 Long-Term Incentive Plan. The restricted stock units were granted to the Reporting Person on February 24, 2014 and vested on December 31, 2016. Settlement of the units for common shares and delivery of the vested shares to the Reporting Person took place on January 17, 2017. /s/Bryan Y. m. Tham, Attorney-in-fact 2017-01-19