144 0001471798 XXXXXXXX LIVE 0000007431 ARMSTRONG WORLD INDUSTRIES INC. 001-02116 2500 Columbia Avenue Lancaster PA 17603 (717) 397-0611 JAMES C MELVILLE Director Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

10000 1260075.00 43700062 08/02/2024 NYSE Common 06/26/2020 Restricted stock vesting under a registered plan Issuer N 1465 06/26/2020 Services Rendered Common 06/17/2022 Restricted stock vesting under a registered plan Issuer N 1406 06/17/2022 Services Rendered Common 06/23/2014 Restricted stock vesting under a registered plan Issuer N 752 06/23/2014 Services Rendered Common 07/13/2018 Restricted stock vesting under a registered plan Issuer N 1558 07/13/2018 Services Rendered Common 07/12/2019 Restricted stock vesting under a registered plan Issuer N 1064 07/12/2019 Services Rendered Common 06/25/2021 Restricted stock vesting under a registered plan Issuer N 992 06/25/2021 Services Rendered Common 06/16/2023 Restricted stock vesting under a registered plan Issuer N 1778 06/16/2023 Services Rendered Common 07/28/2022 Restricted stock vesting under a registered plan Issuer N 229 07/28/2022 Services Rendered Common 02/28/2012 Restricted stock vesting under a registered plan Issuer N 756 02/28/2012 Services Rendered Y 08/02/2024 /s/ James C. Melville