CARC 288 Active

CO-288: Referral Absent

TL;DR

CO-288 means your practice bears the cost of the missing referral denial. Get the referral and resubmit — do not post as a contractual adjustment for this adjustment.

Action

Verify & Resubmit

Who Pays

Provider

Appeal

Yes

Patient Impact

None

Disclaimer

This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does CO-288 Mean?

When CARC 288 appears with Group Code CO, it means the provider is financially responsible for the denied claim because the referral obligation falls on the provider's practice. Under CO, the provider cannot post as a contractual adjustment for services denied due to a missing referral. The practice must absorb the cost unless the referral can be obtained and the claim successfully resubmitted or appealed.

When CARC 288 appears on your remittance advice, the payer is telling you that the services billed required a referral from another physician, and that referral was either never obtained or was not included with the claim submission. Many managed care and HMO plans mandate that patients receive a referral from their primary care physician before seeing a specialist or receiving certain services. Without this referral on file, the payer will not process the claim.

This denial is distinct from a prior authorization denial. A referral is a recommendation from a PCP directing the patient to a specialist, while prior authorization is the payer's advance approval for a specific service. Some plans require both. CARC 288 specifically addresses the absence of the referral component. The denial may also trigger if the referral that was submitted has expired, was issued for the wrong provider, or contained incomplete information such as missing diagnosis codes or an unsigned form.

In most cases, CARC 288 appears with a CO group code, placing the financial responsibility on the provider. This is because obtaining and verifying the referral is considered part of the provider's administrative obligations before rendering services. The good news is that this denial is almost always recoverable if the referral can be obtained retroactively and the claim resubmitted within the payer's timely filing window.

Common Causes

Cause	Frequency
No referral obtained before specialist services The patient saw a specialist or received services that require a referral from a primary care physician, but no referral was obtained or submitted	Most Common
Referral not submitted with the claim A referral was obtained but was not included with or linked to the claim submission	Common
Incorrect or expired referral on file The referral on file has incorrect patient details, wrong procedure codes, or has expired	Common
Out-of-network referral not obtained The patient was referred to an out-of-network provider without obtaining the required referral authorization	Occasional
Referral requirement not identified during scheduling The need for a referral was not identified during the scheduling process and the service was rendered without one	Occasional

How to Resolve

Verify the referral was your responsibility Confirm the patient's plan requires the specialist or rendering provider to have a referral on file. Some payers place this obligation on the patient, which would result in a PR group code instead.
Obtain and attach the referral Contact the PCP's office to get the referral retroactively. Attach it to a corrected claim and resubmit within your payer's filing deadline.
Write off only as last resort If the referral cannot be obtained and the appeal is exhausted, write off the balance. Do not transfer the CO-288 amount to the patient.

Appeal Guide

Obtain the referral from the primary care provider (retroactive if necessary). File an appeal with the referral documentation, medical records, and a letter explaining the clinical circumstances. If a retroactive referral is not available, provide medical necessity documentation and request an exception.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-288:

RARC	Description
N386	Alert: This decision was based on the absence of a required referral. Obtain the missing referral from the primary care provider and resubmit or appeal →
N381	Alert: Consult your contractual agreement for restrictions, billing, and payment information. Review referral requirements in the payer contract for the specific service →

How to Prevent CO-288

Verify referral status during patient check-in before the appointment takes place
Implement automated referral tracking in your EHR that flags patients without active referrals on file
Establish a protocol to contact the PCP's office at least 48 hours before the patient's visit if no referral is on file

General Prevention

Implement a robust referral management system that verifies referrals before scheduling services
Enhance communication with referring providers to ensure referrals are obtained and documented
Train all staff on referral requirements by insurance plan and service type
Utilize EHR and referral management software to track referral status in real-time
Conduct regular audits of referral processes to identify gaps

Also Filed As

The same CARC 288 may appear with different Group Codes:

PR-288 OA-288

Related Denial Codes

CO-284 — Authorization Valid But Does Not Apply to Billed Services CO-296 — Authorization Valid But Does Not Apply to Provider CO-204 — Service/Equipment/Drug Not Covered Under Benefit Plan CO-213 — Non-Compliance with Physician Self-Referral Prohibition CO-219 — Based on Extent of Injury

Sources

https://www.mdclarity.com/denial-code/288
https://resdac.org/sites/datadocumentation.resdac.org/files/Adjustment%20Reason%20Code%20Code%20Table%20(TAF%20Claims).txt
https://x12.org/codes/claim-adjustment-reason-codes
Codes maintained by X12. Visit x12.org for official definitions.