Reference
Insurance Denial Code Directory
What your denial code means — and what you can do about it.
When a health insurance claim is denied, the explanation of benefits (EOB) includes a CARC — Claim Adjustment Reason Code. This code tells you the official reason for the denial. Below is a plain-English guide to the most common CARC codes, what each means, and whether you can appeal it directly.
- Learn more about CARC 1 →CARC 1Provider billing issue
The amount applied to the patient deductible.
This is a standard deductible cost-share — you likely owe this amount. If your deductible has already been met, check the member portal and dispute in writing.
- Learn more about CARC 2 →CARC 2Provider billing issue
The amount applied to patient coinsurance.
This is a standard coinsurance cost-share. You owe this amount unless the percentage applied is incorrect — verify against your Summary of Benefits and Coverage.
- Learn more about CARC 3 →CARC 3Provider billing issue
The amount applied to the patient copayment.
This is a standard copayment. You owe this amount unless the wrong copay tier was applied — check your Summary of Benefits and Coverage for the correct copay by service type.
- Learn more about CARC 4 →CARC 4Provider billing issue
The procedure code is inconsistent with the modifier used or a required modifier is missing.
Usually resolved by your provider's billing office resubmitting with the correct modifier. Ask your provider to review and resubmit before filing a patient appeal.
- Learn more about CARC 7 →CARC 7Patient-appealable
The maximum benefit for this time period has been exhausted.
You may have grounds to appeal this denial directly.
- Learn more about CARC 8 →CARC 8Patient-appealable
The procedure code is inconsistent with the provider type or specialty.
You may have grounds to appeal this denial directly.
- Learn more about CARC 11 →CARC 11Patient-appealable
The diagnosis on the claim does not match the procedure that was billed.
You may have grounds to appeal this denial directly.
- Learn more about CARC 15 →CARC 15Patient-appealable
The authorization number for this service is missing, invalid, or does not match.
You may have grounds to appeal this denial directly.
- Learn more about CARC 16 →CARC 16Provider billing issue
The claim is missing information or has a billing/submission error.
This is usually fixed by your provider resubmitting a corrected claim, not by a patient appeal. Ask your provider's billing office to correct and resubmit first.
- Learn more about CARC 18 →CARC 18Provider billing issue
This is an exact duplicate of a claim already submitted.
Usually a provider billing matter. If the service was genuinely distinct, your provider should resubmit with the correct modifier.
- Learn more about CARC 22 →CARC 22Patient-appealable
This care may be covered by another payer under coordination of benefits.
You may have grounds to appeal this denial directly.
- Learn more about CARC 23 →CARC 23Patient-appealable
The impact of prior payer adjudication has been applied, including payments and/or adjustments.
You may have grounds to appeal this denial directly.
- Learn more about CARC 27 →CARC 27Patient-appealable
Expenses were incurred after your coverage had terminated.
You may have grounds to appeal this denial directly.
- Learn more about CARC 29 →CARC 29Provider billing issue
The time limit for filing this claim has expired (timely filing).
Timely-filing denials are usually the provider's responsibility and the patient typically cannot be balance-billed for them. Confirm with your provider before appealing.
- Learn more about CARC 39 →CARC 39Patient-appealable
Services were denied at the time authorization/pre-certification was requested.
You may have grounds to appeal this denial directly.
- Learn more about CARC 45 →CARC 45Provider billing issue
The charge exceeds the plan's fee schedule or maximum allowable amount.
This is almost always a Contractual Obligation (CO) write-off — the difference is between your provider and the insurer, and you generally owe nothing. This is not a patient appeal situation.
- Learn more about CARC 50 →CARC 50Patient-appealable
The service was denied as not medically necessary by the plan.
You may have grounds to appeal this denial directly.
- Learn more about CARC 55 →CARC 55Patient-appealable
The procedure or treatment is deemed experimental or investigational by the payer.
You may have grounds to appeal this denial directly.
- Learn more about CARC 57 →CARC 57Patient-appealable
The prior authorization or pre-certification was not obtained before the service was rendered.
You may have grounds to appeal this denial directly.
- Learn more about CARC 58 →CARC 58Patient-appealable
The service was provided outside the approved network or geographic service area.
You may have grounds to appeal this denial directly.
- Learn more about CARC 59 →CARC 59Provider billing issue
Payment adjusted based on multiple surgery rules or concurrent anesthesia rules.
Multiple-surgery adjustments are typically a CO provider write-off resolved between your provider and the insurer. Confirm the Group Code — if CO, you generally owe nothing.
- Learn more about CARC 85 →CARC 85Provider billing issue
The claim information does not support the billed service or the total charges are incorrect.
Often a billing error correctable by your provider. Ask your provider's billing office to review and resubmit before filing a patient appeal.
- Learn more about CARC 95 →CARC 95Patient-appealable
The plan's procedures were not followed.
You may have grounds to appeal this denial directly.
- Learn more about CARC 96 →CARC 96Patient-appealable
The charge was denied as a non-covered service.
You may have grounds to appeal this denial directly.
- Learn more about CARC 97 →CARC 97Provider billing issue
Payment for this service is bundled into another service already paid.
Bundling (CARC 97) is usually a CO provider write-off resolved between your provider and the insurer via NCCI rules — you typically owe nothing. Confirm the Group Code before appealing.
- Learn more about CARC 100 →CARC 100Provider billing issue
Payment has been made directly to the patient or insured.
This is informational — payment went directly to you. If your provider is billing you separately for the same service, show them this EOB indicating payment was already made.
- Learn more about CARC 107 →CARC 107Provider billing issue
The related or qualifying claim or service was not identified on this claim.
Typically a billing linkage issue resolved by your provider resubmitting with the correct cross-reference. Ask your provider's billing office first.
- Learn more about CARC 109 →CARC 109Patient-appealable
This claim is not covered by this payer or contractor; it may need to go to another.
You may have grounds to appeal this denial directly.
- Learn more about CARC 119 →CARC 119Patient-appealable
A benefit maximum for this service has been reached.
You may have grounds to appeal this denial directly.
- Learn more about CARC 125 →CARC 125Provider billing issue
Submission or billing error.
Usually a provider billing matter. Ask your provider's billing office to identify and correct the error and resubmit.
- Learn more about CARC 136 →CARC 136Patient-appealable
Failure to follow prior authorization or notification requirements before the service was rendered.
You may have grounds to appeal this denial directly.
- Learn more about CARC 146 →CARC 146Provider billing issue
The diagnosis code submitted is invalid for the date of service billed.
Usually resolved by your provider resubmitting with the correct diagnosis code. Ask your provider's billing office first.
- Learn more about CARC 149 →CARC 149Patient-appealable
The lifetime benefit maximum has been reached for this service or benefit category.
You may have grounds to appeal this denial directly.
- Learn more about CARC 150 →CARC 150Patient-appealable
The payer deems the information submitted does not support this level of service.
You may have grounds to appeal this denial directly.
- Learn more about CARC 151 →CARC 151Patient-appealable
The payer says the information submitted does not support this many/this level of services.
You may have grounds to appeal this denial directly.
- Learn more about CARC 152 →CARC 152Patient-appealable
The payer deems the information submitted does not support this many or this frequency of services.
You may have grounds to appeal this denial directly.
- Learn more about CARC 163 →CARC 163Provider billing issue
Attachment or other documentation referenced on the claim was not received.
Typically resolved by your provider resending the required documentation. Ask your provider's billing or medical records office to resubmit the attachment.
- Learn more about CARC 165 →CARC 165Patient-appealable
A referral was absent or the approved referral limit was exceeded.
You may have grounds to appeal this denial directly.
- Learn more about CARC 167 →CARC 167Patient-appealable
The diagnosis is not covered under the plan.
You may have grounds to appeal this denial directly.
- Learn more about CARC 170 →CARC 170Patient-appealable
Payment is denied when performed or billed by this type of provider.
You may have grounds to appeal this denial directly.
- Learn more about CARC 173 →CARC 173Patient-appealable
The service was not prescribed by an authorized physician or prescriber.
You may have grounds to appeal this denial directly.
- Learn more about CARC 184 →CARC 184Patient-appealable
The referring provider is not eligible to refer the service billed.
You may have grounds to appeal this denial directly.
- Learn more about CARC 185 →CARC 185Patient-appealable
The rendering provider is not eligible to perform the service billed.
You may have grounds to appeal this denial directly.
- Learn more about CARC 188 →CARC 188Patient-appealable
The patient must first be seen by a primary care provider before this service is covered.
You may have grounds to appeal this denial directly.
- Learn more about CARC 197 →CARC 197Patient-appealable
Required precertification, authorization, or notification was absent.
You may have grounds to appeal this denial directly.
- Learn more about CARC 198 →CARC 198Patient-appealable
Precertification, authorization, or notification limits were exceeded.
You may have grounds to appeal this denial directly.
- Learn more about CARC 200 →CARC 200Patient-appealable
Expenses were incurred during a lapse in coverage.
You may have grounds to appeal this denial directly.
- Learn more about CARC 204 →CARC 204Patient-appealable
This service is not covered under your current benefit plan.
You may have grounds to appeal this denial directly.
- Learn more about CARC 252 →CARC 252Provider billing issue
An attachment or additional documentation is required to process this claim.
Usually resolved by your provider submitting the requested records. Ask your provider's billing office first.
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