45 CFR § 156.255
Rating variations
April 14, 2021
(a) Rating areas. A QHP issuer, including an issuer of a multi-State plan, may vary premiums by the geographic rating area established under section 2701(a)(2) of the PHS Act.
(b) Same premium rates. A QHP issuer must charge the same premium rate without regard to whether the plan is offered through an Exchange, or whether the plan is offered directly from the issuer or through an agent.