The Community Rating System (CRS) was introduced to encourage community-level flood mitigation and increase household-level flood insurance uptake through the National Flood Insurance Program (NFIP). Using historical data of policies-in-force and flood damage claims from 1998-2014 for all NFIP communities in Alabama and Mississippi, we estimate the relationship between community participation in the CRS and the number of policies-in-force, as well on flood damage claims. We find a significant, positive, and generally increasing effect of CRS participation on insurance uptake. Reduced flood damage claims are found to be limited to communities with a very high level of CRS participation (Class 5) only.