MSSP Exit More Common Among ACOs Serving Racial, Ethnic Minorities

Accountable care organizations (ACOs) that serve a high proportion of racial and ethnic minorities were more likely to exit the Medicare Shared Savings Program (MSSP) compared to ACOs serving mostly White beneficiaries, according to a study published in JAMA Health Forum.

Starting in 2017, CMS announced several reforms to the MSSP that negatively impacted ACOs caring for racial and ethnic minority groups. First, CMS began incorporating regional trends into MSSP benchmarking calculations without adjusting for social needs. This meant that ACOs serving racial and ethnic minority groups were directly compared to nearby ACOs serving more privileged populations.

Second, CMS announced in 2018 that all ACOs would be required to take on downside risk on an accelerated timeline, which placed additional pressure on ACOs caring for racial and ethnic minorities.

Researchers conducted a retrospective observational study to determine if ACOs serving a high share of racial and ethnic minorities were more likely to exit the MSSP due to these added challenges. The study reflects national data on MSSP ACOs from 2012 to 2018.

The final sample included 589 MSSP ACOs. ACOs whose percentage of beneficiaries who were racial and ethnic minorities ranged between 25.6 percent and 94 percent were considered high-proportion ACOs. ACOs were considered low-proportion if their share of beneficiaries who were racial and ethnic minorities was between 1.5 percent and 25.5 percent.

A quarter of the ACOs (145 ACOs) were high-proportion, while 75 percent (444 ACOs) were low-proportion.

High-proportion ACOs served more beneficiaries with disabilities, dual eligible beneficiaries, and those with higher hierarchical condition case (HCC) risk scores. High-proportion ACOs were also more likely to be physician-led, have a higher share of primary care clinicians, have higher levels of out-of-network care, and serve a higher proportion of low-income individuals.

Between 2012 and 2018, 55 high-proportion ACOs, or 40 percent, earned shared savings in their penultimate year, while 117 low-proportion ACOs, or 26 percent, did the same. High-proportion ACOs were more likely to achieve shared savings in all study years.

However, a greater share of high-proportion ACOs exited the MSSP between 2012 and 2018, the study found. Almost 170 ACOs left the MSSP (29 percent). Among these, 50 were high-proportion ACOs, equaling 34 percent of all high-proportion ACOs. In contrast, 118 low-proportion ACOs exited the MSSP, or 27 percent of all low-proportion ACOs.

Researchers suggested that the regional adjustments to MSSP benchmarks implemented in 2017 may have made it harder for high-proportion ACOs to reach cost targets, prompting them to leave the program.

MSSP exit rates for high-proportion ACOs grew from 1.4 percent in 2014 to 17.3 percent in 2017 and fell to 11.2 percent in 2018. Exit rates for low-proportion ACOs started at 0.8 percent in 2014, rose to 12.3 percent in 2016, and dropped to 9.7 percent in 2018.

A 10-percentage point increase in the share of racial and ethnic minority beneficiaries was associated with a 1.12-fold increase in the odds of MSSP exit. Not earning shared savings, having a higher percentage of beneficiaries with disabilities, and having a higher HCC risk score were also associated with greater odds of MSSP exit.

Additionally, ACOs with a more diverse population were more likely to exit the MSSP than ACOs that mainly served one racial and ethnic group.

While high-proportion ACOs were more likely to exit the MSSP, researchers found that earning shared savings offered stronger protection against exiting for these ACOs compared to low-proportion ACOs.

“This study underscores the importance of effective risk-adjustment methods that incorporate not only medical but also social risk factors to ensure that ACOs are not penalized for taking on patients with complexities, especially because a disproportionately high percentage of these patients are likely to be members of racial and ethnic minority groups,” researchers wrote.

Future policy changes should have an equity-centered approach to ensure that the MSSP and other ACO programs, including the upcoming ACO REACH model, are not exacerbating racial disparities.