24 C.F.R. § 146.35
(a) HUD shall refer to the Federal Mediation and Conciliation Service, a mediation agency designated by the Secretary of Health and Human Services, all complaints that:
(e) HUD shall use the mediation process for a maximum of 60 days after receiving a complaint. Mediation ends if:
(3) Before the end of the 60-day period, the mediator determines that an agreement cannot be reached.
This 60-day period may be extended by the mediator, with the concurrence of HUD, for not more than an additional 30 days if the mediator determines that it is likely that an agreement will be reached during such extended period.