CMS issued a proposed rule Aug. 9 that would make sweeping changes to the Medicare Shared Savings Program, including overhauling the way ACOs share in risks and rewards.

Here are seven things to know about the proposed rule:

1. The redesigned program — which CMS has dubbed “Pathways to Success” — would expand ACO participation agreements from three years to five years and offer eligible ACOs two participationACOs options: “basic” and “enhanced.”

2. The basic track would allow ACOs to participate under an upside-only agreement for one to two years before gradually phasing in higher levels of risk. MSSP ACOs are currently permitted to participate in the upside-only track for up to six years.

3. At the highest level of risk, the basic track would qualify as an advanced alternative payment model under the Quality Payment Program.

4. Under the enhanced track, ACOs would take on risk and qualify as an advanced APM immediately.

5. The proposal would hold ACOs in two-sided models accountable for losses even if they exit midway through a performance year. It would also authorize termination of ACOs with multiple years of poor financial performance.

6. The American Hospital Association expressed concern about the proposal.

“The proposed rule fails to account for the fact that building a successful ACO, let alone one that is able to take on financial risk, is no small task; it requires significant investments of time, effort and finances,” said AHA Executive Vice President Tom Nickels in a statement. “A more gradual pathway is critical for hospitals and health systems that are interested in participating in risk-bearing models — particularly those that are exploring such models for the first time.”

7. Comments on the proposed rule are due Oct. 16.