Washington, May 1 -- Managed care is the most common delivery system for Medicaid. Most states (42, including DC) use comprehensive managed care plans to provide care to at least some of their Medicaid enrollees, according to KFF's updated explainer .

Roughly 3 out of 4 Medicaid enrollees receive care through managed care organizations and payments to these organizations account for over half of total Medicaid spending. Five publicly traded firms - Centene, UnitedHealth Group, Anthem (renamed "Elevance" in 2022), Molina, and Aetna/CVS - account for half of managed care enrollment.

Historically, states have had broad flexibility in defining and enforcing network adequacy standards for managed care organizations. Under the new federal ru...