I did not take time to review the Medicare Manual reimbursement, or claims processing manual, false claims, HIPAA information, or OIG.
If the practice is audited, to defend the differences in prices, the practice needs to demonstrate how it takes more resources to treat/take care of a self-pay patient than a Medicare patient. Going from memory, I was always under the impression you cannot charge any patient differently than a Medicare Patient (under or below). You can have a policy that states you are charging Self-Pay patients the same rate as Medicare, and offering a S/P discount for payment in full.
You will also need to check with your State to see if you are required to charge the S/P patients the same price as the Medicaid Reimbursement.
I work at a facility and we are required to follow the 501R, set-forth by the IRS.
Is the practice under management of a hospital, if so, I encourage you to speak with your compliance officer.