CO-152: Documentation Does Not Support Length of Service

What Does CO-152 Mean?

CO-152 is the standard pairing for this code. The CO group means the provider bears financial responsibility for the duration adjustment — the excess time cannot be billed to the patient. The payer has determined that the clinical records do not support the billed service length under the contractual terms. Providers must either appeal with time documentation or write off the difference between the billed and supported duration.

CARC 152 appears on your remittance when the payer has reviewed your claim and concluded that the clinical documentation does not justify the length or duration of the service that was billed. This is distinct from CARC 150 (level of service) and CARC 151 (frequency of service) — CARC 152 specifically targets how long the individual service lasted.

The most common scenario involves time-based billing codes. If you billed four units of a timed service (indicating 45-60 minutes), but your clinical notes only document 30 minutes of treatment, the payer will deny the excess units with CARC 152. This denial is particularly prevalent in therapy services (physical therapy, occupational therapy, speech therapy), prolonged services, observation care, and anesthesia where time documentation directly drives billing. Missing start and stop times in the clinical record is one of the most frequent triggers.

The denial almost always appears under the CO group code, making the provider responsible for the adjustment. You cannot bill the patient for the time difference. If your clinical records actually do support the billed duration — for example, the clinician documented the treatment time in the narrative but forgot to record start/stop times — an appeal with the full clinical record may succeed. If the documentation genuinely does not support the billed length, correct the claim to reflect the documented duration. Recurring CARC 152 denials are a strong signal that your clinical staff needs training on time documentation requirements for time-based services.

Common Causes

How to Resolve

Verify that your time documentation supports the billed service duration, then either appeal with detailed records or correct the claim to the documented length.

1. Review time documentation Check the clinical notes for start/stop times, total service minutes, and any narrative time references. Verify the documented time supports the billed units.
2. Apply the payer's time rules Calculate the correct number of billable units based on the documented time and the payer's rounding rules. For Medicare therapy services, use the 8-minute rule.
3. Appeal with complete records or correct the claim If the documentation supports the billed duration, appeal with the full clinical record. If it does not, reduce the units to match the documented time and resubmit.
4. Implement time documentation standards If CO-152 is recurring, implement mandatory start/stop time documentation for all time-based services and train clinical staff on the connection between time documentation and billing.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-152:

How to Prevent CO-152

• Document start and stop times for all time-based services as a standard practice
• Train clinical staff on time documentation requirements and the 8-minute rule for therapy services
• Implement EHR templates that prompt clinicians to record service duration for every time-based encounter
• Conduct regular audits of time-based claims to catch documentation gaps before submission

General Prevention

• Document start and stop times for all time-based services to create a clear record of the actual service duration
• Train clinical staff on documentation requirements specific to time-based billing, including the level of detail needed to justify each unit of service
• Implement EHR templates that prompt clinicians to document service duration, medical necessity for the length, and clinical outcomes for each session
• Conduct regular internal audits of time-based service claims to identify documentation gaps before claims are submitted
• Review payer-specific guidelines for service length limitations and ensure billing staff are aware of maximum allowable durations for each service type
• Use automated claim scrubbing tools that compare documented service duration against billed units to catch discrepancies before submission

Also Filed As

The same CARC 152 may appear with different Group Codes:

Related Denial Codes