Section 990.260 - Applicability(a) PHAs that own and operate 250 or more dwelling rental units under title I of the 1937 Act, including units managed by a third-party entity (for example, a resident management corporation) but excluding section 8 units, are required to operate using an asset management model consistent with this subpart.(b) PHAs that own and operate fewer than 250 dwelling rental units may treat their entire portfolio as a single project. However, if a PHA selects this option, it will not receive the add-on for the asset management fee described in § 990.190(f) .