You find out whether the existing doctors take Medicaid. Either call their offices and ask, or research their websites. Doctors typically list the insurances they accept.
You wrote that "all his doctors are not covered under Medicaid", so apparently you've already done some checking.
But the issue of whether he's financially qualified for Medicaid is the important one.
And it helps posters to answer if you don't create separate posts on the same issue.
One doesn't "switch" to Medicaid; a person has to meet the standards to qualify for it.
If you want to get paid, ask your father to enter into a caregiving contract, and do some research here on caregiver payment - you'll see that this question is asked repeatedly. A lot of people want to get paid for taking care of a parent.
You wrote that "all his doctors are not covered under Medicaid", so apparently you've already done some checking.
But the issue of whether he's financially qualified for Medicaid is the important one.
And it helps posters to answer if you don't create separate posts on the same issue.
If you want to get paid, ask your father to enter into a caregiving contract, and do some research here on caregiver payment - you'll see that this question is asked repeatedly. A lot of people want to get paid for taking care of a parent.