I'm looking for some direction on billing OBGYN annual visits. We have a number of patients that have Medicare primary and Commercial ins as secondary. There is some confusion as to whether we should be billing (for example) CPT 99397 to Medicare, which denies, and then it goes to the secondary insurance who typically pays the visit. As another example, we have a patient that came in and CPT 99396 was billed to MCR. MCR denied the claim and forwarded it to the patient's secondary BC plan which placed a balance to the patient co-ins. This is not typical but it is a retiree plan through BC and so I think that may be part of why there is a co-ins. The patient is stating that she never paid before 2021 (when this code was 1st billed), and after review of previous submissions, they billed G0101 in 2013, and then G0439 in 2020 (incorrectly). I would appreciate any assistance regarding this!