A type of contract that provides for a firm price or, under appropriate circumstances, for an adjustable price for the supplies or services being procured.

Time and materials contracts are a type of contract that provides for acquiring supplies or services based on:

• Direct labor hours at specified fixed hourly rates that include wages, overhead, general and administrative expenses and profit.
• Actual cost for materials.

A labor-hour contract is a variation of the time-and-materials contract, differing only in that materials are not supplied by the contractor.

Costs incurred in the contract performance to the extent prescribed in the contract. These contracts may not require completion of the contract work, but rather the best efforts of the contractor. The types of cost reimbursement contracts include:

• Cost.
• Cost-plus-fixed-fee (CPFF).
• Cost-plus-incentive fee (CPIF).
• Cost-plus-award fee (CPAF).

A tool used for acquisition of basic and applied research. BAAs focus on advancing the state-of-the-art or increasing knowledge or understanding — not on a specific system or hardware solution. Visit NSF's Broad Agency Announcements webpage for more information.

NSF generally uses other arrangements for binding non-assistance, contract-like instruments. These arrangements are used for many purposes and are generally intended to be contractual in nature. They generally possess the requirements for a valid, enforceable contract with the United States; these are:

• Mutuality of intent to contract.
• Offer and acceptance.
• Consideration. 

Procurement instruments other than contracts, grants or cooperative agreements that are used for the acquisition of applied research focusing on technology advancement or rapid prototype development.