Only the responsible HHS official can subordinate federal interest to the rights of a lender or other third party. Subordination agreements must be in writing and the mortgage agreement or security agreement for which subordination is requested must comply with §1303.49. When the amount of federal funds already contributed to the facility exceeds the amount to be provided by the lender seeking subordination, the federal interest may only be subordinated if the grantee can show that funding is not available without subordination of the federal interest.