PCPCC commented on the CMS Medicare Shared Savings Program's (MSSP) "Pathways to Success" proposed rule. PCPCC applauded changes to strengthen the program -- particularly for lower revenue, often clinician-led ACOs.   We are, however, concerned by estimates that far fewer organizations would choose to join or remain in the MSSP program. We encouraged CMS to balance its effort to incentivize ACOs to move more quickly to risk with the need to maintain a healthy pool of ACOs moving along the risk continuum.