Medicaid eligibility is determined by income and that threshold varies from state to state. Medicare is a federal program that covers people who qualify from specific groups, mainly people over the age of 65, but also anyone who has been enrolled under disability insurance through social security (SSDI) for 24 months. There are plenty of people enrolled in both. Unfortunately the specifics as well as the quality of assistance will vary wildly from state to state. If your state adopted a healthcare exchange under the ACA I would call them, as they will have the best information in terms of coordinating the different agencies.