The final regulations provide guidance relating to the average income test under section 42(g)(1)(C) of the Internal Revenue Code. If a building is part of residential rental project that satisfies this test, the building may be eligible to earn low-income housing credits. These final regulations affect owners of low-income housing projects, tenants in those projects, and State or local housing credit agencies that administer eligibility for low-income housing credits. These final regulations concern the recordkeeping and reporting requirements for the average income test under section 42(g)(1)(C).