42 U.S.C. § 5193

(a) Federal share The Federal share for assistance provided under this subchapter shall be equal to not less than 75 percent of the eligible costs. (b) Limit on amount of assistance (1) In general Except as provided in paragraph (2), total assistance provided under this subchapter for a single emergency shall not exceed $5,000,000. (2) Additional assistance The limitation described in paragraph (1) may be exceeded when the President determines that— (A) continued emergency assistance is immediately required; (B) there is a continuing and immediate risk to lives, property, public health or safety; and (C) necessary assistance will not otherwise be provided on a timely basis. (3) Report Whenever the limitation described in paragraph (1) is exceeded, the President shall report to the Congress on the nature and extent of emergency assistance requirements and shall propose additional legislation if necessary.