Some people do get full Medicaid on top of getting both Medicare A and Medicare B. In many states, if your income is below a certain level, they will give you Medicaid, as soon as you get on SSDI or SSI. Most people on SSI are getting full Medicare and full Medicaid.

Some people who are on SSDI are not considered poor enough by their states to qualify for full Medicaid. It varies state to state. Some are allowed limited Medicaid benefits.

The type of state aid that pays your Medicare Part B premium for you is a form of Medicaid, though a limited form. Another limited form of Medicaid is one that provides birth control to disabled women, but nothing else. People who get full Medicare and full Medicaid are called "dual eligibles." There are people like that out there.

I was eligible for Medicaid for a short while after I got on SSDI. Then, when I started getting Medicare, my income was considered too high for me to also keep getting full Medicaid in addition to Medicare. My next door neighbor is living on SSI. She gets full Medicare and full Medicaid.

My nextdoor neighbor can go to the dentist on her Medicaid insurance. I can't because I only have limited Medicaid.