NHI seen as threat to HMOs unless uniform benefits set by legislation.
D005380:Financing, Government; D006279:Health Maintenance Organizations / Q000191:economics* / Q000331:legislation & jurisprudence / Q000639:trends; D007342:Insurance Benefits / Q000331:legislation & jurisprudence*; D009310:National Health Insurance, United States / Q000191:economics*; D014481:United States