Question special

Recent data released from HHS' Office of Inspector General indicates that ACO's saved roughly $1 billion in their first three years of operation. Yet the magnitude of this number is minimized when one finds that this number is <1% of the overall Medicare spending for this population of patients. Interestingly, 36 high-performing ACOs contributed $3.4 billion in savings, while lower performing ACOs did not reach their benchmark and increased costs by $2.4 billion. As a result the net savings was $1 billion. Why is there such a discrepancy in ACO performance and how do we improve the low performing ACOs?