42 U.S.C. § 300gg — Fair health insurance premiums

(a) Prohibiting discriminatory premium rates (1) In general: For health insurance sold in the individual or small group market, the premium rate for a plan can only vary based on: (A) (i) Whether the plan covers one person or a family; (ii) The rating area, as set up under paragraph (2); (iii) Age — but the rate cannot vary by more than 3 to 1 between adults; and (iv) Tobacco use — but the rate cannot vary by more than 1.5 to 1. (B) The rate cannot vary based on any other factor not listed in (A). (2) Rating area (A) In general: Each state must set up one or more "rating areas" within the state to apply this subchapter's rules. (B) Secretarial review: The Secretary must review each state's rating areas to make sure they are adequate for this subchapter's purposes. If the Secretary decides a state's rating areas are not adequate, or that a state has not set up rating areas at all, the Secretary may set up rating areas for that state instead. (3) Permissible age bands The Secretary, working with the National Association of Insurance Commissioners, must define the allowed age groups used for the age-based rate variation in paragraph (1)(A)(iii). (4) Application of variations based on age or tobacco use For family coverage under a group health plan or health insurance, the age and tobacco-use rate variations from paragraph (1)(A) apply based on the portion of the premium tied to each family member covered under the plan. (5) Special rule for large group market If a state lets large-group insurers sell coverage through the state's Health Insurance Exchange, then this subsection's rules apply to all coverage sold in that state's large group market — except for self-insured group health plans sold in that market.