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CARC 288 · CO-288

CARC 288 Denial: Referral absent — How to Fix and Appeal

Reviewed by QuickIntell RCM Editorial Team · Last reviewed

Updated

TL;DR

CARC 288 (X12 Referral absent). CARC 288 means no referral was on file at the time of claim adjudication.

Official X12 description

“Referral absent.”

Source: X12 Claim Adjustment Reason Codes. The X12 External Code Lists are the single authoritative source for every CARC descriptor — always verify against the current release before building a claim-scrub rule.

What CARC 288 actually means

CARC 288 means no referral was on file at the time of claim adjudication. This is an HMO-staple denial. The cure is to locate the referral (it may have been issued but not linked to the claim), submit the referral number on a corrected claim, or obtain a retro-referral where the plan allows.

Common root causes

  • Referral never requested; patient self-referred without one.
  • Referral was issued but the referral number or authorization number did not make it onto the 837.

Prevention checklist

  • Scheduling-level referral verification; no appointment without a valid referral for HMO members.
  • EDI mapping that consistently populates the referral number into the correct claim segment.

Appeal strategy — step by step

Most CARC 288 denials clear faster with the right remediation than with a formal appeal. Work the steps in order and escalate only when a lower-effort path has been ruled out.

  1. 1If a valid referral exists, submit a corrected claim with the referral number.
  2. 2If the plan allows retro-referrals, engage the PCP's office within the plan's post-service window.
Sample appeal-letter language for CARC 288
[Provider letterhead] Re: Appeal of CARC 288 — Claim #{claim_number} Member: {member_name} · Member ID: {member_id} Date(s) of Service: {dos} On {remittance_date} this claim was adjusted with CARC 288: "Referral absent." We respectfully request reconsideration. The X12 External Code List definition of CARC 288 does not apply to this claim for the following reasons: 1. [Cite the clinical / coding / policy fact that rebuts the adjustment] 2. [Cite the supporting documentation attached — op note, EOB, LCD/NCD citation, NCCI edit indicator, modifier rationale] 3. [Cite the payer's own policy where applicable] Attached: {list supporting documents} Please process payment under the member's benefits. If additional information is required, contact the billing office at {provider_phone} or {provider_email}. Sincerely, {billing_manager_name}, {credentials}

Edit the bracketed fields before sending. This template is a starting point; a payer-specific appeal form may still be required — check the provider portal first.

Payer-specific notes

Payer-specific behavior for CARC 288 publishes here as the QuickIntell anonymized denial ETL ingests sufficient volume. In the meantime, consult the payer directory for the relevant provider manual and appeal form.

How common is CARC 288?

Search demand rank
#41

Out of 306 seeded CARCs, ranked by combined US monthly search volume for "CARC 288", "CO-288 denial", and "denial code 288".

Platform frequency
Pending ETL

Platform frequency ranks publish once the anonymized denial-rate pipeline reaches the publication threshold (strategy §12 Phase 2).

How QuickRCM prevents CARC 288

QuickRCM catches the root causes above before the 837 leaves the clearinghouse:

  • Claim-scrub rules fire on every root cause listed above — the scrub references the same X12 CAS segment logic that drives the denial, so what the payer checks, QuickRCM checks first.
  • When a denial lands, QuickRCM routes it to the correct worker with the documentation bundle already attached (op note, LCD citation, modifier rationale, EOB, primary 835).
  • Appeal templates tuned to each CARC (including this one) pull the supporting facts from the claim and fill the bracketed fields automatically.
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Frequently asked questions — CARC 288

What does CARC 288 mean?

CARC 288 is an X12 Claim Adjustment Reason Code. The official definition is: "Referral absent." In plain English, the payer is telling you cARC 288 means no referral was on file at the time of claim adjudication. This is an HMO-staple denial. The cure is to locate the referral (it may have been issued but not linked to the claim), submit the referral number on a corrected claim, or obtain a retro-referral where the plan allows.

How do I resolve a CARC 288 (CO-288) denial?

Start with the most common root cause: Referral never requested; patient self-referred without one. First step: If a valid referral exists, submit a corrected claim with the referral number. See the full remediation and appeal checklist on this page before filing a formal appeal.

Is CARC 288 patient responsibility?

No — CARC 288 is typically carried under CO (Contractual Obligation) or OA (Other Adjustment), which means it is the provider's responsibility, not the patient's. Do not bill the patient unless the 835 CAS group code is PR.

What does CARC 288 look like on an EOB or 835 remittance?

On the 835 ERA, CARC 288 appears in Loop 2110 CAS segment as "CAS*CO*288*{amount}". On a paper EOB the same code prints in the Adjustment/Denial Reason column with the X12 description: "Referral absent." — usually paired with one or more RARC remark codes in the same remittance line for additional context.

Which RARC is paired with CARC 288?

CARC 288 is commonly observed with RARC M62, N54. The RARC narrows the reason — for example, pointing at a missing modifier, an LCD citation, or a specific policy. Fix the underlying CARC first; the RARC usually clears with the corrected claim.

Disclaimer

This page is operational reference for medical-billing professionals. It is not legal, clinical, or contractual advice. X12 code descriptors are maintained by the X12 External Code Lists; always verify against the current X12 release and the payer's own published policy before submitting or appealing a claim.