BLDR: Financial results

Item 2.02 Results of Operations and Financial Condition. On October 29, 2026, Builders FirstSource, Inc. issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three and nine months ended September 30, 2026. Item 9.01 Financial Statements and Exhibits. (d) Exhibits. Exhibit No. Description 99.1 News release reporting financial results for the three and nine months ended September 30, 2026, issued by Builders FirstSource, Inc. on October 29, 2026. 104 Cover Page Interactive Data File - the cover page XBRL tags are embedded within the Inline XBRL document All of the information included in Items 2.02 and 9.01 of this report and Exhibit 99.1 hereto is being furnished and shall not be deemed to be “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and shall not be incorporated by reference in any filing under the Securities Act of 1933, as amended. 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 thereunto duly authorized. BUILDERS FIRSTSOURCE, INC. Date: October 29, 2026 By: /s/ Alena Brenner Alena Brenner, Executive Vice President, Chief Legal Officer and Corporate Secretary