Medicaid: A number of US programs of public assistance for persons whose income is insufficient to pay for health care, regardless of age. Medicaid is administered on a state level, with the federal government providing matching funds to state Medicaid programs. Services and options can vary from state to state. Disabled persons who receive Social Security income (SSI), among others, are automatically eligible for Medicaid. To apply for Medicaid, one should contact the local Social Security, public health, or disability services office.