title: A "group of groups" describes the HMO, Intergroup.
mesh_terms: D003365:Costs and Cost Analysis; D006264:Health Benefit Plans, Employee / Q000191:economics; D006279:Health Maintenance Organizations / Q000191:economics / Q000458:organization & administration*; D007087:Illinois; D007196:Indiana; D010820:Physicians / Q000706:statistics & numerical data