To implement the proposed Clinton mental health benefit for the year 2001 requires a capacity to manage a flexible, comprehensive benefit. If fragmentation of services and discontinuity of care are to be reduced, mechanisms must be developed to coordinate services among domains--between acute and chronic care, and among public and private providers. Evidence exists that basic mental health services generally can be managed in health maintenance organizations (HMOs) with considerable cost savings and without detrimental effects on health, but it is less clear whether this is true of services for persons with severe and persistent mental illness. Effective services for persons with severe disorders require a capacity to organize and manage services across broad medical and social areas, but anticipated costs encourage providers to narrow the scope of care they offer and to select low-risk patients. Much will depend on developing methodologies that allow providers to be reimbursed accurately in relation to risk and that protect small providers from the potential cost of acquiring too many high-risk patients.