Avalere reports that the Medicare Shared Savings Program has reduced Medicare spending less than the Congressional Budget Office projected it would in 2010, but boosters of accountable care organizations say the report’s methodology relies on program benchmarks that are designed to calculate provider bonuses, not measure savings. Despite the ACO program costing Medicare in 2016, Avalere said there is evidence that ACO performance improves over time, and ACOs that risk penalties in return for potentially bigger bonuses perform better than...