Medicare: federal, for retirees on Social Security retirement or any retiree who is income qualified. If income exceeds certain levels there are Medicare parts A, B, C, and D, some parts of which are optional coverage that the recipient pays out of pocket for. Medicare is also available to individuals on SSDI, Social Security disability. It is a misconception that Medicare is free to recipients. Nearly all recipients pay at least something in monthly premiums for their coverage

Medicaid: administered by individual states and details of coverage vary by state. Most states have programs to cover children but there are still income limits although they are typically higher (allowed to earn more) than for adults. Children also typically have dental and optical coverage until 18. Most states offer neither to adults.

To further muddy the waters, many Medicare recipients also receive Medicaid to cover copays and sometimes premiums.

I hope this helped and didn’t just make it even more confusing