24 CFR §1000.552

1. (a)This section applies to all financial and programmatic records, supporting documents, and statistical records of the recipient which are required to be maintained by the statute, regulation, or grant agreement.
2. (b)Except as otherwise provided herein, records must be retained for 3 years from the end of the tribal program year during which the funds were expended.
3. (c)If any litigation, claim, negotiation, audit or other action involving the records has been started before the expiration of the 3-year period, the records must be retained until completion of the action and resolution of all issues which arise from it, or until the end of the regular 3-year period, whichever is later.