BLDR: Leadership change

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On May 18, 2026, Builders FirstSource, Inc. (the “Company”) filed a Current Report on Form 8-K (the “Original Form 8-K”) announcing, among other things, that its Board of Directors (the “Board”) appointed Mike Hiller, Chief Talent Officer of the Company, as Chief Operating Officer-Designate effective May 18, 2026, and that Mr. Hiller will succeed Steve Herron, as Chief Operating Officer effective December 31, 2026. In accordance with Instruction 2 to Item 5.02 of Form 8-K, the Company is filing this Amendment No. 1 to the Original Form 8-K (this “Amendment”) to disclose the compensation arrangement approved by the Compensation Committee of the Board for Mr. Hiller in connection with his appointment as Chief Operating Officer, which compensation arrangement had not been determined at the time of the filing of the Original Form 8-K. On October 14, 2026, the Compensation Committee of the Board approved a new compensation arrangement for Mr. Hiller in connection with his appointment as Chief Operating Officer. Effective January 1, 2027, Mr. Hiller will receive a base salary of $675,000 per year, and will be eligible to earn an annual bonus with a target award equal to 125% of his annual salary, based on achievement of performance goals established from year to year by the Compensation Committee of the Board. In addition, Mr. Hiller is eligible to participate in the Company’s Long-Term Incentive Plan. He will also receive a grant of time-based restricted stock units on October 18, 2026, having a grant value equal to $700,000, and vesting in equal annual installments on the first three anniversaries of the grant date. Mr.