What does CO-151 mean?
CARC code 151 is a frequency or quantity denial. The payer is saying the documentation does not support the number of units or visits billed. For behavioral health, this often applies to extended therapy sessions or multiple services on the same day. To appeal, provide clinical documentation that justifies each unit or session, including the clinical rationale for the intensity of treatment. Reference clinical practice guidelines that support the treatment frequency. Success rate is approximately 50%.
How to appeal CO-151
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
Frequency dispute. Appeal with clinical justification for the number of units or visits.