23 C.F.R. § 635.507
(a) Costs, or prices based on estimated costs, under a CM/GC contract shall be eligible for Federal-aid reimbursement only to the extent that costs incurred, or cost estimates included in negotiated prices, are allowable in accordance with the Federal cost principles (as specified in 2 CFR part 200, subpart E). Contracting agencies must perform a cost or price analysis in connection with procurement actions, including contract modifications, in accordance with 2 CFR 200.323(a) and this subpart.
(c) Cost certification.
(3) The certification of final indirect costs shall read as follows:
Certificate of Final Indirect Costs
This is to certify that I have reviewed this proposal to establish final indirect cost rates and to the best of my knowledge and belief:
1. All costs included in this proposal (identify proposal and date) to establish final indirect cost rates for (identify period covered by rate) are allowable in accordance with the cost principles in 2 CFR part 200 subpart E; and
2. This proposal does not include any costs which are expressly unallowable under applicable cost principles of 2 CFR part 200 subpart E.