Section 108(f) of the Act provides for the incontestability of guarantees by HUD under subpart M of this part in the hands of a holder of such guaranteed obligations. If HUD pays a claim under a guarantee made under section 108 of the Act, HUD shall be fully subrogated for all the rights of the holder of the guaranteed debt obligation with respect to such obligation. [61 FR 11481, Mar. 20, 1996]