28 C.F.R. § 90.33
OVW will set aside for this program up to 40 percent of funds appropriated pursuant to 25 U.S.C. 1304(j) , unless otherwise provided by law. The funds set aside for the Tribal Reimbursement Program will be divided into two parts: one part that will guarantee the availability of funds for each participating Tribe that requests reimbursement up to the maximum allowable reimbursement, and one part that will fund waivers of the maximum. In the first year that OVW administers appropriated funds for this program, OVW will allot 25 percent of Tribal Reimbursement Program funds for maximum allowable reimbursements. In subsequent years, OVW may adjust this percentage, based on the appropriations available, the number of participating Tribes, the extent to which participating Tribes expend the maximum allowable reimbursement in the prior year, and the total dollar amount of waivers requested during the prior year. OVW also may consider whether demand for grant funds under the Tribal Jurisdiction Program warrants adjusting this percentage.
28 C.F.R. §90.33