Individuals who are dually eligible for Medicare and Medicaid coverage are known by various terms, such as Medicare-Medicaid enrollees, dual-eligible beneficiaries, dual eligibles, or simply duals. Depending on the context, these terms are often used interchangeably, as they are in this article. In 2016 (the most recent full calendar year with data available), 11.7 million people were dually enrolled in the Medicare and Medicaid programs; among them, nearly 7.0 million (59%) were 65 years or older, while almost 4.8 million (41%) were under age 65 (Medicare-Medicaid Coordination Office, 2017a). Within their respective age groups, dual eligibles represented 14% of all Medicare beneficiaries who were 65 years or older and 51% of all Medicare beneficiaries who were under age 65 and disabled in 2016 (calculations from data accompanying Medicare-Medicaid Coordination Office, 2017a).
Together, dual-eligible beneficiaries comprise an important subset of the Medicare and Medicaid populations, because of their low income levels, high prevalence of chronic conditions and disabilities, substantial care needs, and high medical and long-term care expenditures (Jacobson, Neuman, & Damico, 2012; Young, Garfield, Musumeci, Clemans-Cope, & Lawton, 2013). Dual eligibles account for a disproportionately large share of Medicare and Medicaid spending. In 2013, they represented 20% of all Medicare beneficiaries and 15% of all Medicaid beneficiaries, but incurred 34% of total Medicare spending and 32% of total Medicaid spending (MedPAC & MACPAC, 2018).
Far from homogeneous, dual eligibles are a diverse population with a wide range of circumstances, conditions, and needs (Jacobson et al., 2012). Using the most recent data available, this article first provides a profile of dual eligibles with respect to their demographic characteristics, health conditions, service utilization, and Medicare and Medicaid spending. Then, it highlights the relevance of the dual-eligible population and key policy issues and challenges in the care of this population. To the extent possible, the data presentation and policy discussion focus on dual eligibles aged 65 and older, who constitute the majority of all dual-eligible beneficiaries.