42 CFR § 422.455 - Special rules for MA Regional Plans.
(a) Coverage of entire MA region. The service area for an MA regional plan will consist of an entire MA region established under paragraph (b) of this section, and an MA region may not be segmented as described in § 422.262(c)(2).
(b) Establishment of MA regions -
(1) MA region. The term “MA region” means a region within the 50 States and the District of Columbia as established by CMS under this section.
(2) Establishment -
(i) Initial establishment. By January 1, 2005, CMS will establish and publish the MA regions.
(ii) Periodic review and revision of service areas. CMS may periodically review MA regions and may revise the regions if it determines the revision to be appropriate.
(3) Requirements for MA regions. CMS will establish, and may revise, MA regions in a manner consistent with the following:
(i) Number of regions. There will be no fewer than 10 regions, and no more than 50 regions.
(ii) Maximizing availability of plans. The main purpose of the regions is to maximize the availability of MA regional plans to all MA eligible individuals without regard to health status, or geographic location, especially those residing in rural areas.
(4) Market survey and analysis. Before establishing MA regions, CMS will conduct a market survey and analysis, including an examination of current insurance markets, to assist CMS in determining how the regions should be established.
(c) National plan. An MA regional plan can be offered in more than one MA region (including all regions).