Medicaid
Medicaid is a social health care program for families and individuals with low income and resources, and is the largest source of funding for medical and health-related services for people with low income in the United States.
It is a means-tested program that is jointly funded by the state and federal governments and managed by the states, with each state currently having broad leeway to determine who is eligible for its implementation of the program. States are not required to participate in the program, although all currently do.
Medicaid recipients must be U.S. citizens or legal permanent residents, and may include low-income adults, their children, and people with certain disabilities. Poverty alone does not necessarily qualify someone for Medicaid.
Eligibility is categorical—that is, to enroll you must be a member of a category defined by statute, which includes low-income seniors.