Billing Medicare If You're A Non-Par Provider

I'm a new biller for a doctor who does not participate in Medicare. For patients with Medicare, we charge them the full limiting charge up front and then submit the reimbursement paperwork on their behalf. They receive reimbursement from Medicare and we keep the difference as a copay.

Some patients we'll agree to just accept what Medicare reimburses, either by just requesting the copay at time of visit or no copay at all. As of right now, I've been submitting the claims the same way (as patients who pay everything up front), with the Medicare Patient Request for Medical payment form and then waiting for the patient to receive the check and then tracking them down to sign over the checks to my provider. Obviously not very efficient and of course there's always the risk we don't get anything at all.

As a non-par provider, is there a way to bill Medicare directly and receive payment directly without anything going to patient first? Am I only able to do it electronically? I've tried enrolling in Medicare electronic submission through my clearinghouse, but it requires a PTAN number which, from what I can tell from my research is only given to providers who are enrolled in Medicare.

Am I doing everything all wrong? Is there another option that I don't know about? Any suggestions for the easiest/fastest/most efficient way to bill Medicare directly as a non-par provider?

Thank you so much! I've been trying to figure this out all week and have gotten nowhere. And I'm the only employee for my provider so I have no one else to ask!

Billing Medicare If You're A Non-Par Provider