(a) The contract term may be less than 15 years if HUD finds that, based on the rental charges and financing for the multifamily housing project to which the contract relates, the financial viability of the project can be maintained under a contract having a term less than 15 years. Where a contract of less than 15 years is provided under this paragraph, the amount of rent payable by tenants of the project for units assisted under such a contract shall not exceed the amount payable for rent under section 3(a) of the United States Housing Act of 1937 for a period of at least 15 years.

(b) The contract term may be less than 15 years if the assistance is provided under a contract authorized under section 6 of the HUD Demonstration Act of 1993, and pursuant to a disposition plan under this part for a project that is determined by the HUD to be otherwise in compliance with this part.