Mo. Rev. Stat. § 392.370
After the effective date of an order of the commission which finds, pursuant to section 392.361, that a telecommunications service is sufficiently competitive to justify a lesser degree of regulation, the same, substitutable, or equivalent service offered by a transitionally competitive or noncompetitive telecommunications company shall be classified as transitionally competitive, if the telecommunications service granted a lesser degree of regulation is authorized to be provided anywhere within the certificated or service area of the transitionally competitive or noncompetitive telecommunications company. Any transitionally competitive telecommunications service offered by a noncompetitive local exchange telecommunications company shall be classified as a competitive telecommunications service no later than three years after the effective date of a tariff for such service bearing the classification "transitionally competitive". Any transitionally competitive service offered by a transitionally competitive interexchange telecommunications company shall be classified as a competitive telecommunications service no later than two years after the effective date of a tariff for such service bearing the classification "transitionally competitive". The exchange access rates of an incumbent local exchange company that is declared a competitive telecommunications company shall not exceed the rates that were charged at the time the company became a competitive telecommunications company. The exchange access rates of an alternative local exchange company shall not exceed the exchange access rates of the incumbent local exchange company against whom the alternative local exchange company is competing.
§ 392.370, RSMo