Try this actuarial calculation for percent-of-premium contracts.
D000206:Actuarial Analysis; D002204:Capitation Fee; D003361:Cost Allocation; D005249:Fees and Charges; D006123:Group Practice / Q000191:economics; D006279:Health Maintenance Organizations / Q000191:economics*; D011907:Rate Setting and Review / Q000379:methods*; D020414:Risk Sharing, Financial; D014481:United States