After a non-BIA funding agreement has been executed and the funds transferred to a Tribe/Consortium, can a bureau request the return of unexpended funds?

The non-BIA bureau may request the return of unexpended funds already transferred to a Tribe/Consortium only under the following circumstances: (a) Retrocession; (b) Reassumption; (c) Construction, when there are special legal requirements; or (d) As otherwise provided for in the funding agreement.