Company Update

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549     FORM 8-K/A     (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2023     ARMSTRONG WORLD INDUSTRIES, INC. (Exact name of registrant as specified in its charter)     Pennsylvania 1-2116 23-0366390 (State or other jurisdiction of incorporation or organization) (Commission File Number) (IRS Employer Identification No.)           2500 Columbia Avenue P.O. Box 3001 Lancaster , Pennsylvania   17603 (Address of principal executive offices)   (Zip Code)   Registrant’s telephone number, including area code: ( 717 ) 397-0611 NA (Former name or former address if changed since last report.)     Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))   Securities registered pursuant to Section 12(b) of the Act: Title of each class   Trading Symbol(s)   Name of each exchange on which registered Common Stock, $0.01 par value per share   AWI   New York Stock Exchange Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ◻           Explanatory Note On November 6, 2023 Armstrong World Industries, Inc. (the "Company") issued a press release announcing that its senior management will be hosting investor meetings as part of the Baird Global Industrial Conference on November 7, 2023. In connection with this event, the Company furnished an Investor Presentation on a Current Report on Form 8-K (the "Original Report"). The Company is filing this Amendment No. 1 to Current Report on Form 8-K/A (this "Amended Report") solely to furnish a copy of: (i) a corrected press release correcting a typographical error in the title of Exhibit 99.1. Except as identified above, no other information in the press release or the Investor Presentation furnished with the Original Report has been updated. Section 9 – Financial Statements and Exhibits Item 9.01 Financial Statements and Exhibits. (d) Exhibits No. 99.1 Corrected Press Release of Armstrong World Industries, Inc. dated November 6, 2023 No. 104   Cover Page Interactive Data File (embedded within the Inline XBRL document)       2   SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. ARMSTRONG WORLD INDUSTRIES, INC.     By: /s/ Austin K. So   Austin K. So   Senior Vice President, General Counsel, Secretary and Chief Compliance Officer Date: November 7, 2023   3