William K. Bleser, PhD, MSPH

This study compared beneficiary characteristics and Medicare per capita expenditures among seriously ill Medicare accountable care organization (ACO) populations defined using prospective and retrospective claims-based attribution methods.

From 2013 to 2016, Medicare Shared Savings Program accountable care organizations (ACOs) improved quality. Continued infrastructure development funding, better relationships with postacute care facilities, and shared learnings among diverse ACOs would maximize quality improvement.

From 2013 to 2016, successful Medicare Shared Savings Program accountable care organizations reduced spending by shifting expenditures from the inpatient and postacute care setting to the physician office setting.