There are essentially three corporate structures in the organization:
- Maricopa County Medical Society, established in 1892 and incorporated in 1935, is a not-for-profit voluntary association of physicians which encompasses Maricopa County, the largest and most populated county in Arizona. Currently, MCMS represents over 2,600 physician voices, MDs and DOs, to ensure the quality and preservation of medicine in the county and state of Arizona for both the physicians and patients.
- Medical Society Business Services. This corporation was the result of a merger between the Bureau of Medical Economics, the Telephone Answering Service and Southwestern Preparatory School, which in the 1960's were separate corporations. The physician Board members of the Maricopa County Medical Society also serve on the Board of Directors for the Medical Society Business Services. This corporation currently consists of the Bureau of Medical Economics, Greater Arizona Centralized Credentialing Program, and Round‑up Magazine.
- Arizona Foundation for Medical Care (AFMC), the largest statewide independent healthcare network, was established in 1969 by the Maricopa County Medical Society. AFMC provides a healthcare network that offers highly accessible, quality care for members while focusing on containing healthcare costs for their employers through proactive medical management and wellness programs. AFMC's network includes more than 14,000 professional providers in 39,000 locations throughout Arizona, as well as a comprehensive contracted network of hospitals, laboratories, outpatient surgical facilities, radiology centers and more than 2,500 other ancillary facilities. AFMC is governed by an all physician Board of Trustees.
All of the above corporations are organized under the laws of the State of Arizona as not-for-profit corporations and neither the Medical Society nor the Arizona Foundation pay taxes on the income they receive from their tax-exempt activities. The Medical Society Business Services pays taxes on income from their activities the same as any regular corporation. The not-for-profit status of the Medical Society Business Services merely reflects the fact that they are a wholly owned subsidiary of the Medical Society and have no shareholders.
The Medical Society and its businesses plan to develop services and ideas to benefit medicine and the community in the years to come.