title: By the numbers. Financially vulnerable beneficiaries depend on Medicare HMOs.
authors.forename: W P
authors.initials: WP
authors.lastname: Welch
mesh_terms: D000368:Aged; D003625:Data Collection; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data*; D006801:Humans; D020398:Medicare Part C / Q000706:statistics & numerical data*; D011203:Poverty / Q000706:statistics & numerical data*; D014481:United States