Has anyone received denials from Medicare for in-house mammography or diagnostic x-ray billing the TC (technical component) when mid-level providers are the billing providers? We've never had an issue with this before 7/1/10. Denial code CO-B7 indicates the provider was not certified/eligible to be paid for this service.... I've talked to high level customer service reps who can find no documentation regarding this denial reason code nor have I been able to locate any information on the CMS website regarding this. I was advised to begin appealing these denials and a senior advisor from Medicare is sending this query for analysis. I'm not sure how long that will take and I've submitted an appeal inquiry using the customer care online inquiry form but have not heard anything back yet. Has anyone else experienced this?