17 C.F.R. § 246.13
(a) Definitions. For purposes of this section, the following definitions shall apply:
Currently performing means the borrower in the mortgage transaction is not currently thirty (30) days or more past due, in whole or in part, on the mortgage transaction.
Qualified residential mortgage means a “qualified mortgage” as defined in section 129C of the Truth in Lending Act (15 U.S.C.1639c) and regulations issued thereunder, as amended from time to time.
(b) Exemption. A sponsor shall be exempt from the risk retention requirements in subpart B of this part with respect to any securitization transaction, if:
(4)
(c) Repurchase of loans subsequently determined to be non-qualified after closing. A sponsor that has relied on the exemption provided in paragraph (b) of this section with respect to a securitization transaction shall not lose such exemption with respect to such transaction if, after closing of the securitization transaction, it is determined that one or more of the residential mortgage loans collateralizing the asset-backed securities does not meet all of the criteria to be a qualified residential mortgage provided that: