(ACO) regulations - American Society of Anesthesiologists

CMS-1345-P 268
As ACO size increases from 5,000 to 20,000 (or similarly from 20,000 to 50,000), we
propose blending the MSRs between the two neighboring confidence intervals, resulting
in the MSRs as shown in Table 6. We specify an MSR at both the high and low end of
each range of ACO population size. A particular ACO would be assigned a linearlyinterpolated
MSR given their exact number of beneficiaries. For example, an ACO with
7,500 beneficiaries would be assigned an MSR of 3.3 percent because it lies at the
midpoint between 7,000 and 7,999 beneficiaries, sizes at which the MSR would be 3.4
percent and 3.2 percent, respectively. For ACOs serving more than 60,000 aligned
beneficiaries, we propose that the MSR would not be allowed to fall below 2 percent.
This lower bound is designed to protect the shared savings formula from expenditure
reduction due to random chance that can occur in group claims due to factors that persist
regardless of a group's size. This lower bound is also consistent with the flat 2 percent
MSR we propose to use in the two-sided model and is the minimum level that was used
in the PGP Demonstration for groups regardless of size which also provided a lower
MSR for smaller physician groups participating in the demonstration.
We considered using a flat 95 percent confidence interval for organizations which
is a recognized standard for measuring statistical differences, but as previously noted,
because we believe that many smaller physician-driven and rural ACOs have the
potential to improve the quality and efficiency of care, we were concerned about the
impact on the ability of these ACOs to participate in the Shared Savings Program. We
also wanted to protect the Medicare Trust Funds against large organizations coming
together solely for purposes of aggregating their number of assigned beneficiaries in
order to have smaller MSRs to be able to achieve the minimum required savings levels