D.C. Mun. Regs. tit. 27, § 5030
5030.1 Time-and-materials contracts provide for acquiring supplies or services on the basis of:
(a) Direct labor hours charged at fixed hourly rates that are loaded rates that which include overhead, general and administrative expenses, and profit; and
(b) Materials (which may be charged either at their actual cost or at fixed unit prices).
5030.2 A labor hours contract is a time-and-materials contract that does not involve materials.
5030.3 Both time-and-materials contracts and labor hours contracts should specify a ceiling price.
SOURCE: Final Rulemaking published at 65 DCR 4406 (April 20, 2018).