The evolution of quality management in Medicaid managed care.

Since the early 1990s almost all states have moved some or all of their Medicaid beneficiaries to Medicaid managed care (MMC). Critics have worried about quality since MMC's inception. Proponents argued that state Medicaid agencies, as large-scale purchasers of care, would pursue "value-based purchasing" and other strategies to stimulate quality improvements. In this paper we extend and update previous evaluations of the use of managed care for the Medicaid population, the extent to which beneficiaries receive care from Medicaid only and from commercial health plans, and the quality management programs that state Medicaid agencies supported during 2001.