On July 9, the Centers for Medicare and Medicaid Services (CMS) released a proposed rule describing its Comprehensive Care for Joint Replacement (CCJR) payment model, a pilot bundled payment program for major lower extremity joint replacements. While CMS’ increasing interest in bundled payments has been apparent, the announcement of this mandatory initiative was a surprise to many, given that the Bundled Payments for Care Improvement (BPCI) demonstration program is still in its early stages for many participants. In addition, CMS recently requested comments on the expansion of the BPCI program, which it states is not related to the CCJR pilot. Nonetheless, CCJR, which will be mandatory for about 1,200 hospitals, appears poised for implementation in January 2016. This article presents an overview of the CCJR program, highlighting its major components and comparing it to the BPCI program.  Obviously, we summarized and omitted some of the details of the 438-page CMS proposal, so...