Hi, I find Medicare as secondary quite confusing especially since we are out of network with all primary insurances. Many times I get remittance advice code oa23 and on bottom of claim patient responsibility= total claim amount. I’ve seen this on era files as well as hard remits. Only time I don’t get that is when primary insurance applies to deductible. In that case patient responsibility on claim is shown as Medicare allowed. I get that and bill patient mcare amount. My question is oa23 supposed to be a write off even though on claim patient responsibility shows full amount? I called cms and they are not very helpful. I understand they won’t pay as primary amount is greater but question is patient responsibility the amount shown on Medicare eob it is oa23 supposed to be write off always?