Will I be changed over to Medicare at age 65?

It's possible to have both. The Medicaid may pick up the cost of the Medicare premium, your prescription costs, etc. depending on the state you live in and the amount of your income. Your state probably has information on-line about benefits of Medicaid and how it interacts with Medicare. Also get the Medicare booklet that explains benefits for this year. Call and ask about extra help in paying Medicare premiums for low income people. You don't want to end up paying for the Medicare premium every month and end up with less coverage than you probably have on Medicaid.

Nothing happens automatically at 65 unless you are already on Social Security. If you are on Social Security (because you took early payment as opposed to because of disability), you will get a Medicare package three months before your 65th birthday. That package will explain how Medicare and Medicaid will work together. You may or may not still be eligible for Medicaid; it depends on your finances and the state you live in

No, your Medicaid will continue as long as you need it. If you were NOT on Medicaid, you would apply for Medicare at 65. You are all set.