What does CO-50 mean?
CARC code 50 is a medical necessity denial and is one of the most important denials to appeal in behavioral health. The payer is saying the service you provided was not medically necessary based on the information submitted. To appeal, you need strong clinical documentation including treatment plans, progress notes, and clinical assessments that demonstrate why the service was necessary. Reference the payer's own clinical coverage policies, AMA CPT guidelines, and if applicable, APA practice guidelines. For behavioral health, cite the DSM-5 diagnostic criteria and how the patient meets them. Success rate is approximately 55%, making this well worth the appeal effort given the typically high dollar amounts.
How to appeal CO-50
Check the RARC code
The RARC (Remittance Advice Remark Code) on your ERA provides specific details about why the claim was denied. This tells you exactly what needs to be fixed.
Gather clinical documentation
Compile clinical notes, treatment plans, and any relevant guidelines that support the medical necessity of the service provided.
Submit a formal appeal letter
Write a detailed appeal letter that references clinical guidelines, payer policies, and includes supporting documentation. Submit via the payer's preferred method (fax, portal, or mail).
Key notes for behavioral health
Requires clinical documentation. Reference payer policy, AMA guidelines, peer-reviewed literature.