It began operations as a County Organized Health System in 1994,[4] and is currently the largest Medi-Cal Managed Care Plan in Northern California.

Other coverage programs have been included in the past:[7] In 1993, the State Department of Health Services produced a report entitled “Expanding Medi-Cal Managed Care: Reforming the Health System – Protecting Vulnerable Populations” which served as a blueprint for expansion of Medi-Cal managed care.

[11] The Coalition began discussing overall health of the Solano County community in 1988 culminating in a contract with the State of California in 1992, beginning operations in 1994.

Further geographic expansions are listed[13] The founding Chief Executive Officer was Jack Horn, who retired in 2015.

[17] Partnership HealthPlan is governed by a board of commissions composed of up to 40 members representing all 24 counties, including physicians, county officials, hospital leaders, providers, PHC health plan members, and public representatives.