The mortgage shall provide for:

(a) A single aggregate payment each month for all payments to be made by the mortgagor to the mortgagee.

(b) The mortgagor to pay to the mortgagee:

(1) Interest and principal on the first day of each month in accordance with an amortization plan agreed upon by the mortgagor, the mortgagee and the Commissioner.

(i) Date of first payment to interest shall be the endorsement date or, where there are insured advances, the initial endorsement date.

(ii) Date of first payment to principal. The Commissioner shall estimate the time necessary to complete the project and shall establish the date of the first payment to principal so that the lapse of time between completion of the project and commencement of amortization will not be longer than necessary to obtain sustaining occupancy.

(2) An amount on each interest payment date sufficient to accumulate in the hands of the mortgagee one payment period prior to its due date, the next annual mortgage insurance premium payable by the mortgagee to the Commissioner. Such payments shall continue only so long as the contract of insurance shall remain in effect.

(3) Equal monthly payments as will amortize the ground rents, if any, and the estimated amount of all taxes, water charges, special assessments, and fire and other hazard insurance premiums, within a period ending one month prior to the dates on which the same become delinquent.

(4) The mortgage shall further provide:

(i) That such payments shall be held by the mortgagee, for the purpose of paying such items before they become delinquent.

(ii) For adjustments in case such estimated amounts shall prove to be more, or less, than the actual amounts so paid therefor by the mortgagor.

(c) The mortgagee to apply each mortgagor payment received to the following items in the order set forth:

(1) Premium charges under the contract of mortgage insurance.

(2) Ground rents, taxes, special assessments, and fire and other hazard insurance premiums.

(3) Interest on the mortgage.

(4) Amortization of the principal of the mortgage.