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.

COO — Mr. Hiller: The filing discloses the compensation details for Mr. Hiller's appointment as COO and a transition role for Mr. Herron, which are internal personnel changes rather than a loss of a senior executive.

President, Technology and Digital Solutions — Gayatri Narayan: Ms. Narayan was notified of her separation from the company.

Results of Operations and Financial Condition. On July 30, 2026, Builders FirstSource, Inc. issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three and six months ended June 30, 2026.

Director — Mark A. Alexander: Mr. Alexander resigned from the Board due to health reasons.

Chief Operating Officer — Steve Herron: Steve Herron is retiring after over 15 years of dedicated service, and Mike Hiller will succeed him as Chief Operating Officer.

Results of Operations and Financial Condition. On April 30, 2026, Builders FirstSource, Inc. issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three months ended March 31, 2026.

Other Events. On April 30, 2026, the Company issued the news release attached hereto as Exhibit 99.2 announcing that the Company’s board of directors authorized the repurchase of up to $500 million of the Company’s outstanding shares of common stock.

Results of Operations and Financial Condition. On February 17, 2026, Builders FirstSource, Inc. issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three and twelve months ended December 31, 2025.

Results of Operations and Financial Condition. On October 30, 2025, 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, 2025.

Results of Operations and Financial Condition. On July 31, 2025, Builders FirstSource, Inc. issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three and six months ended June 30, 2025.

Entry into a Material Definitive Agreement On May 20, 2025, Builders FirstSource, Inc. (the “Company”) replaced its existing revolving commitments of $1,800.0 million (the “Previous Revolving Facility”) with new revolving commitments of $2,200.0 million (the “New Revolving Facility”), extended the maturity date of the New Revolving Facility and made certain other amendments to the New Revolving Facility, with Bank of America, N.A. (“Bank of America”), as administrative agent and collateral ag…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant The information set forth under

Entry into a Material Definitive Agreement 6.750% Senior Notes due 2035 On May 8, 2025 (the “Closing Date”), Builders FirstSource, Inc., a Delaware corporation (the “Company”), completed the previously announced sale of $750.0 million aggregate principal amount of its 6.750% senior notes due 2035 (the “Notes”) at an issue price of 100.0% (the “Notes Offering”). The Company used the net proceeds from the Notes Offering to repay indebtedness outstanding under the Company’s senior secured ABL fa…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant The information set forth under

Regulation FD Disclosure. Notes Offering On May 5, 2025, Builders FirstSource, Inc. (“Builders FirstSource” or the “Company”) issued a press release to announce that it intends, subject to market and other conditions, to offer (the “Offering”) $500 million aggregate principal amount of senior unsecured notes due 2035 (the “Notes”) as set forth in a preliminary offering circular dated May 5, 2025. Any Notes issued in connection with the Offering would be issued in a private transaction that is…

Results of Operations and Financial Condition. On May 1, 2025, Builders FirstSource, Inc. (the “Company”) issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three months ended March 31, 2025.

Other Events. On May 1, 2025, the Company issued the news release attached hereto as Exhibit 99.2 announcing that the Company’s board of directors authorized the repurchase of up to $500 million of the Company’s outstanding shares of common stock.

Results of Operations and Financial Condition. On February 20, 2025, Builders FirstSource, Inc. (the “Company”) issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three and twelve months ended December 31, 2024.

Director — Cheryl Ainoa, Maria Renz: The company appointed two new directors with significant experience in digital transformation and technology.

President & Chief Executive Officer — Dave Rush: Dave Rush is retiring as President & Chief Executive Officer, and Peter Jackson will succeed him in the role.

principal accounting officer — Matt Trester: Matt Trester was promoted to principal accounting officer.

Results of Operations and Financial Condition. On November 5, 2024, Builders FirstSource, Inc. (the “Company”) issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three and nine months ended September 30, 2024.

President & Chief Executive Officer — Dave Rush: Peter Jackson was appointed as the next President & Chief Executive Officer, succeeding Dave Rush who is retiring after 25 years of service.

Results of Operations and Financial Condition. On August 6, 2024, Builders FirstSource, Inc. (the “Company”) issued the news release attached hereto as Exhibit 99.1 reporting its financial results for the three and six months ended June 30, 2024.