How does Medicaid differ from Medicare?

Medicaid is a joint federal-state program that provides health coverage primarily to low-income individuals and families, with eligibility based on income and other factors (and rules that vary by state, since states administer their own programs within federal guidelines). Medicare, by contrast, is a federal program based mainly on age (65+) or disability, regardless of income. Some individuals qualify for both ('dual eligibles'). The key distinction is the basis of eligibility: Medicaid is needs-based (income), while Medicare is age/disability-based. Because state Medicaid rules differ, exam answers often note this variation. This Medicare-versus-Medicaid distinction is commonly tested.