A key difference between Medicare and Medicaid is that one is primarily age-based and the other is an income-based welfare program benefiting people with limited financial resources, regardless of age.
Medicare is available to assist people of 65 or older, and in some cases people under 65 with specific medical disabilities or diseases. It applies to the qualified individual and not an entire family.
Medicaid is jointly run by the state and federal governments whose eligibility is based on income rather than age or disability. Medicaid was developed to help people and families with limited financial resources get health care.
Additionally, you can apply for Medicaid at any time your situation warrants it, you do not have to wait for an open enrollment period. In most cases, people who qualify for Medicaid may be exempt from the individual penalty. Whereas, when you apply for Medicaid outside the open enrollment period you may be penalized.
Also, Medicaid coverage and eligibility varies from state to state due to the fact that it is both federally and state managed. Medicare basics are standard.