Over 12 million Americans are eligible for both Medicare and Medicaid, including roughly 7.5 million adults aged 65 and over and roughly 4.5 million people with disabilities under age 65. Many of these dual-eligible individuals have complex health care needs, and most receive care in uncoordinated Medicare and Medicaid fee-for-service delivery systems, where Medicare pays for their hospital, primary care and preventive care services and Medicaid pays for their long-term services and supports (LTSS), such as nursing facility and home health services, and most behavioral health care.