25 CFR §170.228

1. (a)A Tribe can use TTP funds to leverage other funds.
2. (b)A Tribe can use TTP funds to pay back loans or other finance instruments (including those provided through an agreement with another Tribe) that were used for a project that:
   1. (1)The Tribe paid for in advance of the current year using non-TTP funds;
   2. (2)Was included in FHWA-approved TTPTIP; and
   3. (3)Was included in the NTTFI at the time of construction.