45 CFR § 75.375 - Effects of suspension and termination.
Costs to the non-Federal entity resulting from obligations incurred by the non-Federal entity during a suspension or after termination of a Federal award or subaward are not allowable unless the HHS awarding agency or pass-through entity expressly authorizes them in the notice of suspension or termination or subsequently. However, costs during suspension or after termination are allowable if:
(a) The costs result from obligations which were properly incurred by the non-Federal entity before the effective date of suspension or termination, are not in anticipation of it; and
(b) The costs would be allowable if the Federal award was not suspended or expired normally at the end of the period of performance in which the termination takes effect.