Vesting issues in retiree medical plans.
D000368:Aged; D006264:Health Benefit Plans, Employee / Q000331:legislation & jurisprudence*; D006279:Health Maintenance Organizations; D006801:Humans; D007348:Insurance, Health / Q000331:legislation & jurisprudence*; D010415:Pensions; D011243:Preferred Provider Organizations; D014481:United States