to carry out the flood mitigation assistance grant program under section 1366 of the National Flood Insurance Act of 1968 ( 42 U.S.C. 4104c ). 307. Community Rating System Improvements (a) Provision of community rating system premium credits to maximum number of communities practicable Subsection (b) of section 1315 of the National Flood Insurance Act of 1968 ( 42 U.S.C. 4022(b) ) is amended— (1) in paragraph (2), by striking may and inserting shall