A Firm Fixed Price Construction contract as described by FAR 16.202-1 provides for a price that is not subject to any adjustments on the basis of the contractor’s cost experience. This contract type places maximum risk upon the contractor and full responsibility for all cost resulting profit or loss, while imposing a minimum administrative burden upon the contracting parties.

Q: Can a Contracting Officer / The Government, convert one element (a line item within the schedule of values) of a firm-fixed-price construction contract into a cost-reimbursable item after an award has been made?

A: No, not without the consent of the contractor through a modification to the contract award. http://docs.law.gwu.edu/asbca/decision/pdf2000/52889.pdf (Re. ASBCA No. 52889) .

Q. Can a Contracting Officer / The Government, claim an overpayment if a contractor receives payment for a element of work, but cannot produce an invoice for that specific amount when asked to provide supporting documentation of the work element's invoice?

A: No, under a Firm-Fixed-Price Contract the contractor may assert "indirect cost" and other allowable cost within each element of work. If a Contracting Officer deems it necessary to adjust elements of work within a Schedule of Value the CO must do this prior to dispersing and accepting the first requisition of payment or prior to award. http://docs.law.gwu.edu/asbca/decision/pdf2000/52889.pdf (Re. ASBCA No. 52889)