The Federal Trade Commission and the Justice Department proposed a safe harbor from antitrust laws for smaller, newly created accountable care organizations. The enforcement agencies also proposed an expedited review under antitrust laws for larger ACOs that dominate at least half of providers' service areas.

Authorities unveiled the plan (PDF) as the CMS released long-awaited proposed accountable care organization rules for Medicare under the Patient Protection and Affordable Care Act.

The newly created safe harbor would apply to ACOs that account for as much as 30% of Medicare fee-for-service business in local services areas. Hospitals must determine their inpatient share of local service areas for all insurers when possible.

The threshold would be measured by service—such as primary care or specialties—when at least two independent providers within an ACO offer the same service in the same area.

ACOs with at least half of Medicare fee-for-service business in a local service area must undergo an antitrust review. Under the proposal, reviews would be expedited and close within 90 days after necessary documents are received by authorities. The FTC and the Justice Department would use less-stringent criteria to review private-market ACOs already approved by the CMS to operate under Medicare, as long as private-market networks operate the same as Medicare ACOs do.

ACOs must include otherwise-independent providers and must have been created after the March 23, 2010 passage of the Affordable Care Act to be eligible under the policy.

Accountable care groups with 30% to 50% of local-service-area business may seek an expedited antitrust review under the policy.