D.C. Mun. Regs. tit. 27, r. 27-4612
Fixed price contracts include several variants:
Unlike cost reimbursement contracts, any type of fixed price contract obligates the contractor to complete the contractually-specified work for a fixed price.
A firm fixed price contract provides for a price that is not subject to adjustment, except in the event of a change to the scope of work.
A fixed price contract with economic price adjustment provides for an upward or downward adjustment in the stated contract price based on changes in certain benchmarks specifically identified in the contract (for example, catalog prices or the producer price index for a particular commodity), subject to a ceiling on upward adjustments.
A fixed price incentive contract generally provides for establishing a final price by applying a formula based on the relationship between the total cost actually incurred by the contractor and a total target cost. A fixed price incentive contract results in the parties sharing in the cost savings or increases associated with differences between the actual and target cost. These contracts also can include incentive formulas based on the contractor's schedule or technical performance.
D.C. Mun. Regs. tit. 27, r. 27-4612