Instantly find explanations, causes, and resolution steps for every Claim Adjustment Reason Code (CARC) and Remark Code.
Claim Adjustment Reason Codes (CARC) explain why a payment differs from what was billed. Every 835 ERA and EOB uses these standardized codes.
Search any code or keyword above. Each page includes the full description, common causes, resolution steps, and appeal guidance.
Each denial code page also links to a dedicated Remark Code page — optimized for providers searching for ERA remark code context.
Most denials are reversible. Our guides walk you through the correct steps to correct, resubmit, or formally appeal each denial type.
| Code | Description | View |
|---|---|---|
| N112 | This claim is excluded from your electronic remittance advice. | Details → |
| N112 | This claim is excluded from your electronic remittance advice. | Details → |
| N113 | Only one initial visit is covered per physician, group practice or provider. | Details → |
| N113 | Only one initial visit is covered per physician, group practice or provider. | Details → |
| N114 | During the transition to the Ambulance Fee Schedule, payment is based on the lesser o… | Details → |
| N114 | During the transition to the Ambulance Fee Schedule, payment is based on the lesser o… | Details → |
| N115 | This decision was based on a Local Coverage Determination (LCD). An LCD provides a gu… | Details → |
| N115 | This decision was based on a Local Coverage Determination (LCD). An LCD provides a gu… | Details → |
| N115 | These are non-covered services because this is not deemed a 'medical necessity' by th… | Details → |
| N115 | Non-covered charge(s) Procedure code billed is not correct/valid for the services bi… | Details → |
| N115 | Policy frequency limits may have been reached, per LCD | Details → |
| N115 | There is a date span overlap or overutilization based on related LCD | Details → |
| N115 | A recent break in medical need 13/15 months have been paid Same and Similar equipme… | Details → |
| N116 | Alert: This payment is being made conditionally because the service was provided in t… | Details → |
| N116 | Alert: This payment is being made conditionally because the service was provided in t… | Details → |
| N117 | This service is paid only once in a patient's lifetime. | Details → |
| N117 | This service is paid only once in a patient's lifetime. | Details → |
| N118 | This service is not paid if billed more than once every 28 days. | Details → |
| N118 | This service is not paid if billed more than once every 28 days. | Details → |
| N119 | This service is not paid if billed once every 28 days, and the patient has spent 5 or… | Details → |
| N119 | This service is not paid if billed once every 28 days, and the patient has spent 5 or… | Details → |
| N12 | Policy provides coverage supplemental to Medicare. As the member does not appear to b… | Details → |
| N12 | Policy provides coverage supplemental to Medicare. As the member does not appear to b… | Details → |
| N120 | Payment is subject to home health prospective payment system partial episode payment … | Details → |
| N120 | Payment is subject to home health prospective payment system partial episode payment … | Details → |
| N121 | Medicare Part B does not pay for items or services provided by this type of practitio… | Details → |
| N121 | Medicare Part B does not pay for items or services provided by this type of practitio… | Details → |
| N122 | Add-on code cannot be billed by itself. | Details → |
| N122 | Add-on code cannot be billed by itself. | Details → |
| N123 | Alert: This is a split service and represents a portion of the units from the origina… | Details → |
| N123 | Alert: This is a split service and represents a portion of the units from the origina… | Details → |
| N124 | Payment has been denied for the/made only for a less extensive service/item because t… | Details → |
| N124 | Payment has been denied for the/made only for a less extensive service/item because t… | Details → |
| N125 | Payment has been (denied for the/made only for a less extensive) service/item because… | Details → |
| N125 | Payment has been (denied for the/made only for a less extensive) service/item because… | Details → |
| N126 | Social Security Records indicate that this individual has been deported. This payer d… | Details → |
| N126 | Social Security Records indicate that this individual has been deported. This payer d… | Details → |
| N127 | This is a misdirected claim/service for a United Mine Workers of America (UMWA) benef… | Details → |
| N127 | This is a misdirected claim/service for a United Mine Workers of America (UMWA) benef… | Details → |
| N128 | This amount represents the prior to coverage portion of the allowance. | Details → |
| N128 | This amount represents the prior to coverage portion of the allowance. | Details → |
| N129 | Not eligible due to the patient's age. | Details → |
| N129 | Not eligible due to the patient's age. | Details → |
| N13 | Payment based on professional/technical component modifier(s). | Details → |
| N13 | Payment based on professional/technical component modifier(s). | Details → |
| N130 | Consult plan benefit documents/guidelines for information about restrictions for this… | Details → |
| N130 | Consult plan benefit documents/guidelines for information about restrictions for this… | Details → |
| N130 | These are non-covered services because this is not deemed a 'medical necessity' by th… | Details → |
| N130 | The equipment is billed as a purchased item when only covered if rented. | Details → |
| N130 | Claim was submitted to incorrect contractor Was beneficiary inpatient on date of ser… | Details → |
| N130 | Noncovered item Item is not medically necessary for DME | Details → |
| N131 | Total payments under multiple contracts cannot exceed the allowance for this service. | Details → |
| N131 | Total payments under multiple contracts cannot exceed the allowance for this service. | Details → |
| N132 | Alert: Payments will cease for services rendered by this US Government debarred or ex… | Details → |
| N132 | Alert: Payments will cease for services rendered by this US Government debarred or ex… | Details → |
| N133 | Alert: Services for predetermination and services requesting payment are being proces… | Details → |
| N133 | Alert: Services for predetermination and services requesting payment are being proces… | Details → |
| N134 | Alert: This represents your scheduled payment for this service. If treatment has been… | Details → |
| N134 | Alert: This represents your scheduled payment for this service. If treatment has been… | Details → |
| N135 | Record fees are the patient's responsibility and limited to the specified co-payment. | Details → |
Medical claim denial codes — formally known as Claim Adjustment Reason Codes (CARC) — are standardized identifiers maintained by the X12 standards body and used across all Medicare, Medicaid, and commercial payer 835 electronic remittance transactions. When a claim is paid at a different amount than billed, at least one CARC code must accompany the remittance advice to indicate the specific reason for the adjustment.
The most frequently encountered codes include CO-16 (missing or invalid claim information), CO-45 (charges exceeding fee schedule), PR-1 (patient deductible), CO-29 (timely filing deadline exceeded), and CO-4 (procedure code inconsistent with modifier). Each represents a distinct, actionable reason that has a defined resolution pathway.