24 CFR § 983.205 - Term of HAP contract.
(a) Initial term. The PHA may enter into a HAP contract with an owner for an initial term of up to 20 years for each contract unit. The length of the term of the HAP contract for any contract unit may not be less than one year, nor more than 20 years.
(b) Extension of term. The PHA and owner may agree at any time before expiration of the HAP contract to execute one or more extensions of the HAP contract term. The following conditions apply:
(1) Each extension executed must have a term that does not exceed 20 years;
(2) At no time may the total remaining term of the HAP contract, with extensions, exceed 40 years;
(3) Before agreeing to an extension, the PHA must determine that the extension is appropriate to continue providing affordable housing for low-income families or to expand housing opportunities; and
(4) Each extension must be on the form and subject to the conditions prescribed by HUD at the time of the extension.