Medical Disability Insurance appears to be a reference to Long Term Disability Insurance. As such, that is a policy that would pay part of your income back to you during an extended time of being unable to perform your job due to illness or injury.
If referring to Medicare Disability, that it is the benefit received through Social Security if unable to work due to disability.
If referring to Medicare Disability, that it is the benefit received through Social Security if unable to work due to disability.