Request for Proposals for Modeling, Simulation, Engineering, Analysis, and Tactics (MSEAT)

***ONLY SEAPORT MAC HOLDERS are eligible for award under this solicitation.*** Request for Proposal (RFP) under the Seaport NxG Multiple Award Contract (MAC), number N6133126R3105 for Modeling, Simulation, Engineering, Analysis, and Tactics (MSEAT). This RFP will also be posted within the Seaport NxG Opportunities Page. This effort has been previously been posted within the Seaport NxG portal under the Opportunities page as the following: Source Sought Notice N61331-25-SN-Q38, dated 7/11/2025 and the follow-up Advance Planning Notice/Pre-Solicitation Notice dated 11/7/2025. Previous references this potential solicitation as number N6133126R3006. *** RESPONSES MUST BE SUBMITTED VIA THE PIEE SOLICITATION MODULE.*** PLEASE UTILIZE THE DOCUMENTS FOUND WITHIN THE SEAPORT NxG ANNOUCEMENT, Opportunity - Modeling, Simulation, Engineering, Analysis, and Tactics (MSEAT) RFP N6133126R3105. Opportunity Type: Other. *** PLEASE REFER TO THE AMENDMENT LOG FOUND WITHIN THE SEAPORT ANNOUNCEMENT FOR UPDATES TO THE RFP.**** * Amendment 0001 - 1/9/2026 The purpose of this amendment is to: 1. Incorporate omitted attachments J.11 Labor Rate Workbook and J.12 GFP List to the solicitation in the PIEE Solicitation Module. 2. Amend Section L, paragraph 3.2, to change the past performance evaluation period from three years to five years preceding the release of the solicitation to ensure consistency with the criteria outlined in Section M, Factor 2. 3. Replace Section J Attachment J.4 Cost Summary Format with Attachment J.4 Cost Proposal Spreadsheet. 4. Update verbiage in clauses L-215-H006 Submission of Questions by Offerors--Basic (NAVSEA) (APR2022) and L-216-H0001 Task Order General Information (NAVSEA) (JUL 2023) to support proposal submission in the PIEE Solicitation Module. 5. Update verbiage in Section L, 1.0 Instructions of Offers and Section L, Volume III, 3.3.1 - 3.3.3 to support proposal submission in the PIEE Solicitation Module. 6. Insert Volume IV, 3.4.2 Solicitation Fill-ins to provide additional instructions to offerors.