HMOs reach out to Medicare beneficiaries.
D000368:Aged; D002908:Chronic Disease; D003625:Data Collection; D018588:Fee-for-Service Plans; D006279:Health Maintenance Organizations / Q000191:economics* / Q000706:statistics & numerical data; D006801:Humans; D006278:Medicare / Q000706:statistics & numerical data*; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D014481:United States