Wasn't there a bill sometimes referred to as "RISA" -- I think -- that would jail doctors for 2 years and $10K who refused Medicare/Medicaid patients...later overturned.
OR
Would jail them if they treated patients who *weren't* on Medicare if they accepted *any* Medicare patients in the last 2 years?
I don't think you can be put in jail by Medicare-yet.
However, you cannot treat a Medicare patient outside of the system without being banned from Medicare-which, for most primary care types means being put out of business.