SMS monitors Medigap policy sales.
D000368:Aged; D000369:Aged, 80 and over; D003258:Consumer Behavior; D006299:Health Services for the Aged / Q000191:economics*; D006801:Humans; D007348:Insurance, Health / Q000592:standards*; D006278:Medicare / Q000191:economics*; D011243:Preferred Provider Organizations / Q000592:standards*; D014922:Wisconsin