What is the difference between Medicare and Medicaid?

The short answer is that Medicaid is a poverty program and Medicare isn't. Many disabled people who get Medicaid get it because they are on Supplemental Security Income (SSI). This is called “categorical” Medicaid eligibility. To get SSI and thereby get Medicaid you have to be poor and disabled. Medicaid pays doctors at very low rates. People who have only Medicaid can have a hard time finding doctors willing to take them on as patients. Medicaid does pay for prescription medications. Medicaid can go back up to three months prior to the date of a Medicaid claim. Note that it is possible to apply for Medicaid directly - through a local Medicaid office - without having a companion claim for SSI.

For Medicare it does not matter whether you are rich or poor. If you have been on Disability Insurance Benefits, Disabled Widows or Widowers Benefits or Disabled Adult Child Benefits for 24 months you qualify for Medicare. The good thing about Medicare is that it pays doctors at a higher rate than Medicaid. Almost all doctors are happy to take Medicare patients. The bad things about Medicare are that it does not begin until after a person has been on cash disability benefits for two years and that it generally does not pay for prescription medications.