PMA Medical Specialists L.L.C., a group of 54 physicians with offices in Chester, Delaware, Montgomery and Philadelphia Counties, has applied with a Maryland company to form an Accountable Care Organization with 7,800 Medicare beneficiaries, the group said Tuesday.

Accountable Care Organizations, or ACOs, are designed to improve care and reduce costs by emphasizing coordination. Typically, Medicare and the ACO share the savings, if there are any.

PMA's partner in Aledade Freedom ACO is Aledade, a Bethesda firm that in June announced the formation of a separate ACO with Gateway Medical Associates. The Gateway ACO, if approved, will cover 6,200 Medicare beneficiaries through eight locations in Chester and Delaware Counties, Aledade said.

The applications for both ACOs are pending at the Centers for Medicare and Medicaid Services.