Apples and oranges...In my case they legally have to wave copay as I have QMB which means I'm a Qualified Medicare benificary which gives me 100% coverage for Medicade as well and I also receive extra help and this is hard for them to grasp they may only charge me for a small copay for Medicade 3.50 nothing above the approved amount and because it's such a different type of coverage they constantly try to bill for the 15% by law over the approved amount and they keep saying they don't take Medicade but it doesn't make a difference if they accept Medicare these are there rules! It's taken me year's to figure it out so I don't expect them to be up to code as you say
With Medicare, a provider can either be
a) Medicare with assignment
b) Medicare without assignment
c) non-participant with Medicare.
A provider who accepts assignment with Medicare, then they agree to accept the Medicare approved charge. For example, if the provider bills $1000 dollars for a service, and Medicare's allowable is $50, then the provider may only collect $50 and cannot collect the difference of $950. As a patient, you are still responsible for the deductible and co-insurance
If a provider accepts Medicare WITHOUT assignment, they are allowed to bill up to a 15% premium on the Medicare allowable. In the above example, they are allowed to bill up to $57.50, though that may be further limited by state regulations. A provider who does not take assignment, is also allowed to bill you upfront and require you to file reimbursement from Medicare using form CMS 1490S.
So, is your provider accepting Medicare with or without assignment?
Medicaid has nothing to with the equation as in your situation, Medicaid would be secondary, and would what Medicare doesn't pay up to the maximum allowable by Medicare. If the provider does not take Medicaid then you are still responsible for the amount up to what Medicare doesn't cover, up to either the Medicare allowable if your provider takes assignment or the allowable + 15% if your provider doesn't take assignment.
There is also a 3rd scenario (scenario c), where a provider opts-out of Medicare. In this scenario, the provider can charge any amount and is not subjective to Medicare allowable rates, but this is a very unusual and rare situation.
The reason I say post #20 is irrelevant to the original post, is that post #19 has nothing to do with coding and the legality of billing 2 "visits"
Insurance is very complex and there are too many scenarios to generalize. Often times, these type of posts have much missing background information, but I hope the above explanation will at least provide insight for the OP in post #19