CO-150 Denial Code: Level of Service Not Supported

What CO-150 means

CARC 150 says the payer deems the information submitted does not support this level of service. Many services come in levels: E/M visits, some therapy and behavioral health services, critical care, and certain procedures with complexity tiers. The payer reviewed your claim or records and concluded the documentation supports a lower level than you billed.

CO-150 can arrive in two forms. Some payers deny the line outright and expect a corrected claim; others pay at a lower level and report the difference as CO-150. Look at the paid amount and any remark code before acting.

Example: a practice bills a high-level established patient visit. After records review, the payer decides medical decision making was moderate, pays at the level below, and reports the difference as CO-150 with remark M25.

Common causes

• Documentation that does not show the medical decision-making complexity required for the level billed.
• Time-based levels billed without total time documented, or with time that does not meet the threshold.
• Cloned or templated notes that do not show visit-specific work.
• Payer claim-editing software that automatically adjusts levels based on diagnosis or patient history.
• A mismatch between diagnoses on the claim (box 21) and the complexity implied by the level.
• Billing a high level for a visit whose main purpose was a minor or routine problem.

How to fix it

1. Check the remittance for what was paid and which remark code applies.
2. Review the note against the code definition and guidelines in effect on the date of service.
3. If the documentation supports the level, file an appeal or reconsideration with the full note and a brief summary of how each requirement was met (problems, data, risk, or total time).
4. If it supports a lower level, send a corrected claim with the right code (resubmission code 7 in box 22), or accept the downcoded payment if the payer already paid the lower level.
5. Refund the patient if you collected cost-sharing based on the higher level.
6. Watch for patterns. If a payer downcodes automatically, raise it with provider relations and ask for its policy.

How to prevent it

• Train providers on current E/M and level-selection guidelines, especially when they change.
• Document time when time is the basis for the level, and document decision-making when it is not.
• Audit a sample of visit levels regularly, comparing your distribution to specialty norms.
• Use templates that prompt for visit-specific findings instead of copying forward.
• Track downcoding by payer with an ERA Analyzer to catch automated level adjustments.

Specialty notes

Behavioral health practices billing psychotherapy by duration should document start and stop times or total face-to-face time; a session billed at a longer duration than documented may be adjusted under CARC 150. PT/OT practices with evaluation complexity levels need documentation that shows the elements required for the complexity billed.