31 C.F.R. § 515.333

The term depository institution means any of the following:

(a) An insured bank as defined in section 3 of the Federal Deposit Insurance Act;

(b) An insured institution as defined in section 408(a) of the National Housing Act;

(c) An insured credit union as defined in section 101 of the Federal Credit Union Act; or

(d) Any other institution that is carrying on banking activities pursuant to a charter from a Federal or state banking authority.