44 CFR §208.44

1. (a)Except as allowed under paragraph (b) of this section, DHS will not reimburse other costs incurred preceding, during or upon the conclusion of an Activation unless, before making the expenditure, the Sponsoring Agency has requested, in writing, permission for a specific expenditure and has received written permission from the Program Manager or his or her designee to make such expenditure.
2. (b)At the discretion of the Program Manager or his or her designee, a request for approval of costs presented after the costs were incurred must be in writing and establish that:
   1. (1)The expenditure was essential to the Activation and was reasonable;
   2. (2)Advance written approval by the Program Manager was not feasible; and
   3. (3)Advance verbal approval by the Program Manager had been requested and was given.