48 CFR § 16.205-3
Limitations
November 17, 2020
This contract type shall not be used unless—
(a) Negotiations have established that (1) the conditions for use of a firm-fixed-price contract are not present (see 16.202-2), and (2) a fixed-price incentive contract would not be more appropriate;
(b) The contractor's accounting system is adequate for price redetermination;
(c) The prospective pricing periods can be made to conform with operation of the contractor's accounting system; and
(d) There is reasonable assurance that price redetermination actions will take place promptly at the specified times.