(a) Five or more family units; requirements
Notwithstanding any provision of this subchapter that is inconsistent with this section, the Secretary may insure, under any provision of this subchapter providing for insurance of mortgages on properties including 5 or more family units, a mortgage secured by a first lien on the property that (1) provides for the mortgagee to share in a predetermined percentage of the property's net appreciated value; and (2) meets such other conditions, including limitations on the rate of interest which may be charged, as the Secretary may require by regulation.

(b) Payment of mortgagee's share of net appreciated value; term of mortgage; repayment; "net appreciated value" defined
The mortgagee's share of a property's net appreciated value shall be payable upon maturity or upon payment in full of the loan or sale or transfer (as defined by the Secretary) of the property, whichever occurs first. The term of the mortgage shall not be less than 15 years, and shall be repayable in equal monthly installments of principal and fixed interest during the mortgage term in an amount which would be sufficient to retire a debt with the same principal and fixed interest rate over a period not exceeding 30 years. In the case of a mortgage which will not be completely amortized during the mortgage term, the principal obligation of the mortgage may not exceed 85 percent of the estimated value of the property or project. For purposes of this section, the term "net appreciated value" means the amount by which the sales price of the property (less the mortgagor's selling costs) exceeds the actual project cost after completion, as approved by the Secretary. If there has been no sale or transfer at the time the mortgagee's share of net appreciated value becomes payable, the sales price for purposes of this section shall be determined by means of an appraisal conducted in accordance with procedures approved by the Secretary and provided for in the mortgage.

(c) Entitlement of mortgagee upon default
In the event of a default, the mortgagee shall be entitled to receive the benefits of insurance in accordance with section 1713 of this title, but such insurance benefits shall not include the mortgagee's share of net appreciated value. The term "original principal face amount of the mortgage" as used in section 1713 of this title shall not include the mortgagee's share of net appreciated value.

(d) Maximum percentage of net appreciated value; disclosure requirements
The Secretary shall establish by regulation the maximum percentage of net appreciated value which may be payable to a mortgagee as the mortgagee's share. The Secretary shall also establish disclosure requirements applicable to mortgagees making mortgage loans pursuant to this section, to assure that mortgagors are informed of the characteristics of such mortgages.

(e) Inapplicability of State constitution, statute, etc., limiting or prohibiting increases in outstanding loan balance
Mortgages insured pursuant to this section which contain provisions for sharing appreciation or which otherwise require or permit increases in the outstanding loan balance which are authorized under this section or under applicable regulations shall not be subject to any State constitution, statute, court decree, common law, rule, or public policy limiting or prohibiting increases in the outstanding loan balance after execution of the mortgage.

(f) Number of dwelling units
The number of dwelling units included in properties covered by mortgages insured pursuant to this section in any fiscal year may not exceed 5,000.