An Orange County doctors group has signed an agreement to join ApolloMed ACO, a subsidiary of Apollo Medical Holding Inc. in Glendale, the company announced Thursday.

ApolloMed ACO is an accountable care organization, a type of company that coordinates care between doctors, hospitals and other providers to improve outcomes for Medicare patients. National health care reform has given new relevance to ACOs.

Under the agreement, Apollo will work with Physician Partners IPA in Garden Grove, a network of 50 primary care physicians and specialists, by analyzing clinical data, managing high-risk patients and coordinating care among different facilities and doctors.

Apollo announced a similar deal on Sept. 16 with Integrated Healthcare Holdings Inc., a company that owns four hospitals in Orange County.

“We are very excited to be building an integrated physician network in Orange County that will deliver more efficient care while focusing on each patient’s needs,” said Dr. Warren Hosseinion, chief executive of Apollo, in a statement.

Apollo share were unchanged at 56 cents in the over-the-counter market on zero volume.