Headquarters Building (HQB) Mechanical and Electrical Upgrades at the Mike Monroney Aeronautical Center (MMAC), Oklahoma City, OK.

SIR 6973GH-26-R-00082 and Attachments 1 through 16 are provided for potential offerors

Amendment 0001 is hereby issued to to provide the Site Visit Attendees, provide Addendum 01 to the Specifications and Drawings included with this SIR, incorporate new AMS Clause 3.6.2-50, Implementation of E.O. 14398(INTERIM April 2026) and incorporate revised AMS Clauses 3.6.1-4 Small Business Subcontracting Plans (INTERIM April 2026) and 3.10.1-15, Changes-Construction, Dismantling, Demolition, or Removal of Improvements (INTERIM April 2026), revise the Minimum Offer Acceptance Period on Page 1, Block 11 of the SIR and AMS Clause 3.2.2.3-2, Minimum Offer Acceptance Period, revise the date for submission of Questions and extend the closing date of the SIR.

Amendment 0002 is hereby issued to revise Provision M.3 RELEVANT EXPERIENCE AND PAST

PERFORMANCE EVALUATION (REVISED MAY 15, 2026).

Amendment 0003 is hereby issued to incorporate Amendment 0003, Attachment 1 - Questions and Answers, Attachment 2 - Addendum 02, Attachment 3 - Asbestos Abatement Information, Attachment 4 - HQB Furniture Information, and Attachment 5 - HQB Requested Photos.

Amendment 0004 is hereby issued to remove Pages 1 and 2 of the Original SIR, Solicitation, Offer and Award, and incorporate New Pages 1 and 2, Solicitation, Offer and Award (Construction, Alteration, or Repair) attached. In addition, Amendment 0004 provides New Questions and Answers 160 through 165 (attached), establishes a firm cut-off date for submission of questions and extends the proposal due date to June 5, 2026. NOTE: OFFERORS ARE TO SUBMIT NEWLY INCORPORATED PAGES 1 AND 2, SOLICITATION, OFFER AND AWARD (CONSTRUCTION, ALTERATION, OR REPAIR) WITH THEIR PROPOSAL.