42 CFR §510.105

1. (a)General. The geographic areas for inclusion in the CJR model are obtained based on a stratified random sampling of certain MSAs in the United States.
   1. (1)All counties within each of the selected MSAs are selected for inclusion in the CJR model.
   2. (2)Beginning with performance year 3, the selected MSAs are designated as either mandatory participation MSAs or voluntary participation MSAs.
   3. (3)Beginning with performance year 6, only the 34 MSAs designated as mandatory participation MSAs as of performance year 3.
2. (b)Stratification criteria. Geographic areas in the United States are stratified according to the characteristics that CMS determines are necessary to ensure that the model is tested on a broad range of different types of hospitals that may face different obstacles and incentives for improving quality and controlling costs.
3. (c)Exclusions. CMS excludes from the selection of geographic areas MSAs that met the following criteria:
   1. (1)Had fewer than 400 episodes between July 1, 2013 and June 30, 2014.
   2. (2)Had fewer than 400 non-Model 1, 2, or 4 BPCI episodes as of October 1, 2015.
   3. (3)Failed either or both of the following rules regarding participation in BPCI:
      1. (i)More than 50 percent of eligible episodes initiated in a BPCI Model 2 or 4 initiating hospital.
      2. (ii)More than 50 percent of eligible episodes that included SNF or HHA services, where the SNF or HHA services were furnished by a BPCI Model 3 initiating HHA or SNF.
   4. (4)For MSAs including both Maryland and non-Maryland counties, more than 50 percent of eligible episodes were initiated at a Maryland hospital.