This report studies the pricing of negatively elevated structures in the National Flood Insurance Program. Current NFIP methods for calculating risk-based premiums for these structures, including risk analysis, flood maps, and engineering data are examined. The report also evaluates alternative approaches for calculating risk-based premiums and discusses engineering hydrologic and property assessment data needs to implement full risk-based premiums. The findings and conclusions of this report will help to improve the accuracy and precision of loss estimates for negatively elevated structures, which in turn will increase the credibility, fairness, and transparency of premiums for policyholders.