24 CFR §203.415

1. (a)If the mortgage was accepted for insurance pursuant to a commitment issued prior to September 2, 1964, the mortgagee may, by filing a written request with the application for debentures, receive in addition to the debentures and the cash adjustment check, a certificate of claim issued in accordance with section 204(e) of the Act. This certificate shall become payable (if at all) as prescribed in section 204(f) of the Act.
2. (b)If the mortgage was accepted for insurance pursuant to a commitment issued on or after September 2, 1964, or under the Direct Endorsement, Lender Insurance, or Coinsurance programs, no certificate of claim will be issued.