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CARC 284 · CO-284

CARC 284 Denial: Precertification/authorization/notification/pre-treatment number may be valid b… — How to Fix and Appeal

Reviewed by QuickIntell RCM Editorial Team · Last reviewed

Updated

TL;DR

CARC 284 (X12 Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the bille…). CARC 284 means an authorization number is on file, but it doesn't match what was billed — wrong code, wrong DOS, wrong provider, or wrong facility.

Official X12 description

“Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the billed services.”

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 284 actually means

CARC 284 means an authorization number is on file, but it doesn't match what was billed — wrong code, wrong DOS, wrong provider, or wrong facility. Pull the auth record, compare to the claim, and either correct the claim to match the auth (if clinically appropriate) or request an auth amendment with the treating clinician's rationale.

Common root causes

  • Auth was approved for a different CPT/HCPCS than what was ultimately performed.
  • Auth approved for a different provider or facility than where the service was rendered.
  • Auth expired or was for a different date range.

Prevention checklist

  • Day-of-service confirmation that auth code, performing provider, and facility on record match the planned service.
  • Post-service auth-amendment workflow for surgical code changes discovered intra-op.

Appeal strategy — step by step

Most CARC 284 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. 1Request an auth amendment with the operative note or clinical rationale for the code/provider change.
  2. 2If the auth truly does not cover what was done, submit a retroactive authorization request per plan policy.
Sample appeal-letter language for CARC 284
[Provider letterhead] Re: Appeal of CARC 284 — Claim #{claim_number} Member: {member_name} · Member ID: {member_id} Date(s) of Service: {dos} On {remittance_date} this claim was adjusted with CARC 284: "Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the billed services." We respectfully request reconsideration. The X12 External Code List definition of CARC 284 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 284 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 284?

Search demand rank
#64

Out of 306 seeded CARCs, ranked by combined US monthly search volume for "CARC 284", "CO-284 denial", and "denial code 284".

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 284

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 284

What does CARC 284 mean?

CARC 284 is an X12 Claim Adjustment Reason Code. The official definition is: "Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the billed services." In plain English, the payer is telling you cARC 284 means an authorization number is on file, but it doesn't match what was billed — wrong code, wrong DOS, wrong provider, or wrong facility. Pull the auth record, compare to the claim, and either correct the claim to match the auth (if clinically appropriate) or request an auth amendment with the treating clinician's rationale.

How do I resolve a CARC 284 (CO-284) denial?

Start with the most common root cause: Auth was approved for a different CPT/HCPCS than what was ultimately performed. First step: Request an auth amendment with the operative note or clinical rationale for the code/provider change. See the full remediation and appeal checklist on this page before filing a formal appeal.

Is CARC 284 patient responsibility?

No — CARC 284 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 284 look like on an EOB or 835 remittance?

On the 835 ERA, CARC 284 appears in Loop 2110 CAS segment as "CAS*CO*284*{amount}". On a paper EOB the same code prints in the Adjustment/Denial Reason column with the X12 description: "Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the billed services." — usually paired with one or more RARC remark codes in the same remittance line for additional context.

Which RARC is paired with CARC 284?

CARC 284 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.