CO-122: Psychiatric Services Reduction

What Does CO-122 Mean?

CO-122 places the psychiatric service reduction on the provider as a contractual obligation. The most frequent trigger is the Medicare 2% sequestration, which automatically reduces all Part B payments including mental health services. This reduction is built into the payment calculation and cannot be appealed or billed to the patient. Beyond sequestration, CO-122 may indicate the payer reduced payment due to documentation deficiencies, coding errors, or failure to obtain required pre-authorization — in those cases, correcting the issue and resubmitting or appealing is appropriate.

CARC 122 indicates that the payer has reduced payment for psychiatric or mental health services. This code is specific to behavioral health claims and signals that the payer applied a reduction based on plan terms, regulatory requirements, or documentation deficiencies related to the psychiatric care provided.

The most common scenario triggering CARC 122 under CO is the Medicare sequestration — a 2% automatic payment reduction applied to all Medicare Part B claims, including psychiatric services. This reduction is mandated by federal budget legislation and is non-appealable. Providers must simply absorb the 2% as a contractual adjustment. Beyond sequestration, CO-122 can also fire when the payer reduces payment due to incomplete clinical documentation, missing pre-authorization, or coding errors that prevent the payer from validating the psychiatric services billed.

Under PR, the code appears when the patient has exhausted their psychiatric benefit limits — many commercial plans cap the number of mental health visits or the dollar amount covered for behavioral health services within a plan year. Once the cap is reached, additional charges shift to the patient. The group code distinction is critical: CO means the provider writes off the difference, while PR means the patient owes the balance. Always check the RARC codes accompanying CARC 122 for specific guidance on the reduction reason.

Common Causes

How to Resolve

Determine whether the reduction is a standard contractual adjustment or a correctable error, then write off or appeal accordingly.

1. Determine if the reduction is sequestration Check whether the reduction equals approximately 2% of the allowed amount on a Medicare Part B claim. If so, this is standard and non-appealable.
2. Review coding and documentation for errors If the reduction exceeds the sequestration amount, review the claim for coding errors, missing modifiers, or documentation gaps that may have caused an additional reduction.
3. Correct and resubmit or write off Correct any identified errors and resubmit the claim. If the reduction is purely contractual, post it as a write-off.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-122:

How to Prevent CO-122

• Maintain complete clinical documentation for every psychiatric session including treatment plans, progress notes, and medical necessity justification
• Obtain required pre-authorization before rendering psychiatric services to avoid authorization-related reductions
• Use correct CPT codes and diagnosis codes for mental health services, including appropriate modifiers
• Conduct regular audits of psychiatric claims to catch documentation and coding issues before submission

General Prevention

• Ensure complete and detailed clinical documentation for all psychiatric services, including treatment plans, progress notes, and medical necessity justification
• Verify insurance coverage and obtain required pre-authorization before providing psychiatric services
• Maintain up-to-date knowledge of coding guidelines specific to mental health services to avoid coding-based reductions
• Conduct regular internal audits of psychiatric claims to identify and correct documentation or coding patterns that trigger reductions

Also Filed As

The same CARC 122 may appear with different Group Codes:

Related Denial Codes