24 C.F.R. § 3282.306
The Secretary shall, on the basis of reports submitted by the State, and on the basis of HUD monitoring, make a continuing evaluation of the manner in which each State is carrying out its State plan and shall submit the reports of such evaluation to the appropriate committees of the Congress. Whenever the Secretary finds, after affording due notice and opportunity for a hearing in accordance with subpart D of this part, that in the administration of the State program there is a failure to comply substantially with any provision of the State plan or that the State plan has become inadequate, the Secretary shall notify the State of withdrawal of approval or conditional approval of the State program. The State program shall cease to be in effect at such time as the Secretary may establish.
24 C.F.R. §3282.306