HUD Handbook 4350.3 § 3-4

Owners are required to determine whether applicants are eligible to occupy the
         subsidized property and receive housing assistance. Eligibility is determined by federal
         statute and HUD regulation. For HUD programs, eligibility is only determined at move-in
         or at initial certification, *(e.g. when a Section 236 tenant starts receiving Section 8
         assistance)* except as discussed in paragraphs 3-13, Determining Eligibility of Students
         for Assistance and 3-16, Determining the Eligibility of a Remaining Member of a Tenant
         Family. HUD's general eligibility requirements are found in HUD's regulations at 24
         CFR, part 5.