A mortgage loan shall be secured by a lien against the mortgaged property. Real property securing a loan shall meet the requirements of the Fund. An escrow account for payment of taxes, insurance, homeowner association fees, condominium fees, or other customary expenses related to a mortgage loan, as applicable, shall be satisfactory to the Fund. A mortgage may not exceed a term of 40 years unless the Secretary, by written determination for a particular loan or category of loans, agrees to a term exceeding 40 years. A mortgage shall bear interest at the rate agreed on by the lender and the borrower, and committed to by the Fund. A mortgage shall conform to the required documentation and eligibility criteria required by the Fund.