CO-11Contractual Adjustment
Diagnosis does not support the procedure
What this code means
The insurer says the diagnosis code on your claim does not justify the procedure that was billed. This is often a coding mismatch, not a clinical judgment.
What to do next
Request an itemized bill from your provider. Verify that the diagnosis and procedure codes are accurate. If correct, appeal with clinical documentation showing why the procedure was necessary for your diagnosis.
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