(a) A creditor and consumer may agree to any provision in the credit transaction that is expressly authorized in a program for residential mortgage loans by the United States, including the Office of Thrift Supervision, the Office of the Comptroller of the Currency, or the Department of the Treasury.
(b) If a creditor and consumer agree on an alternative residential mortgage loan from a program described by Subsection (a), the creditor shall comply with all limitations and requirements, including required disclosures, of the regulating entity that relate to the loan.