CMO was founded by Montefiore Medical Center as part of the hospital's strategic tenet: to build and sustain a strong community-based healthcare system for the large urban population it serves in the Bronx, a 42-square-mile city of 1.3 million people, on the outskirts of Manhattan.

Prior to establishing CMO, Montefiore had spent 30 years building a dynamic healthcare delivery system that consisted of two general hospitals, dozens of ambulatory centers, skilled nursing and rehabilitation facilities, numerous primary care programs reaching into public schools, substance abuse clinics, homeless shelters and other organized resources to respond to the needs of the community. In 1995, it was ready to organize its entire provider community-hospitals, all full-time physicians and as many voluntary doctors as chose to participate - into a single integrated provider association (IPA). It was then that it established CMO as the care management organization through which the IPA would contract with virtually every HMO offering plans in the geographic area.

From 1995 to 1999, CMO continued to grow and support Montefiore's IPAs: investing in managed care capabilities, developing disease management programs and investing in information technology that would ensure quality and coordinated service across its expanding network. By 1999, CMO was supporting over 50,000 enrollees.

In the next five years, CMO continued to grow its infrastructure, resources and services. Its disease management programs were proving to increase member compliance with treatment plans and lower hospital admissions.

Today, CMO supports a provider network of 2,400 credentialed professionals, managing more than 105,000 covered lives in global risk arrangements and another 74,000 lives under various specialty capitation programs. Almost three-quarters of all Medicare Advantage members in the Bronx, or 22,700 members, are managed by CMO. CMO is one of 12 organizations nationally, and the only provider-sponsored network, to be selected by the Center for Medicare and Medicaid Services to participate in a demonstration project to evaluate the value of disease management for patients with chronic illnesses.