12 U.S.C. § 1709: State constitutional and legal limits upon interest chargeable on loans, mortgages, or other interim financing arrangements; applicability; covered arrangements

any loan or mortgage which is secured by a one- to four-family dwelling and which is (A) insured under title I or II [ 12 U.S.C. 1702 et seq. or 1707 et seq.] of the National Housing Act, or (B) insured, guaranteed, or made under chapter 37 of title 38; or any temporary construction loan or other interim financing if at the time such loan is made or financing is arranged, the intention to obtain permanent financing substantially by means of loans or mortgages so insured, guaranteed, or made is declared. The provisions of this section shall apply to such loans, mortgages, or other interim financing made or executed in any State until the effective date (after June 30, 1976 ) of a provision of law of that State limiting the amount of interest which may be charged, taken, received, or reserved on such loans, mortgages, or financing.