Medicaid managed care: the last bastion of the HMO?

States rely on health maintenance organizations (HMOs) for their Medicaid beneficiaries because they offer guaranteed access to comprehensive benefits at a predictable cost. This is true despite movement away from HMOs, or at least the more restrictive variants, in the private sector. Plans that focus on Medicaid are becoming more central to states' programs as commercial plans exit. Publicly traded, Medicaid-focused plans are also emerging. Medicaid participating plans are aggressively managing costs and care, contrasting sharply with commercial insurance where the trend is toward less intrusive managed care. In this context, state Medicaid managed care programs are facing important policy challenges related to plan participation, mainstreaming, and product design.