Medicare and Medicaid are two totally different programs. Medicare is a federally funded and federally distributed catastrophic health insurance program which comes into play to everyone automatically when they reach the age of 65.
At age 65, Medicare becomes the primary health insurance carrier and any other carrier becomes a secondary carrier. Medicaid is a federally created, and state administered, program that provides health insurance to low-income children, seniors and people with disabilities. In addition, it covers care in a nursing home for those who qualify.