(a) The Regional Administrator may provide up to 60 percent of the approved work plan costs in any fiscal year. The non-federal share of costs must be provided from non-federal sources.

(b) The Regional Administrator may increase the maximum federal share if the Tribe or Intertribal Consortium can demonstrate in writing to the satisfaction of the Regional Administrator that fiscal circumstances within the Tribe or within each Tribe that is a member of the Intertribal Consortium are constrained to such an extent that fulfilling the match requirement would impose undue hardship. In no case shall the federal share be greater than 90 percent.