Billing rate as used in this subpart means an indirect cost rate
(1) established temporarily for interim reimbursement of incurred indirect costs and(2) adjusted as necessary pending establishment of final indirect cost rates.
48 C.F.R. §42.701
48 FR 42370, Sept. 19, 1983, as amended at 59 FR 11387, Mar. 10, 1994; 63 FR 9064, Feb. 23, 1998; 66 FR 2133 , Jan. 10, 2001