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 |
|---|---|---|
| 183 | Subacute This service has been down graded to Subacute | Details → |
| 183 | The referring provider is not eligible to refer the service billed. Usage: Refer to t… | Details → |
| 183 | The units of service are missing or invalid. | Details → |
| 184 | Telemetry This service has been down graded to Telemetry | Details → |
| 184 | The prescribing/ordering provider is not eligible to prescribe/order the service bill… | Details → |
| 184 | Charge is missing or $0.00; invalid (rate X days not equal to charge); or CPT categor… | Details → |
| 185 | Obs 2 This service has been down graded to the Observation Rate | Details → |
| 185 | The rendering provider is not eligible to perform the service billed. Usage: Refer to… | Details → |
| 185 | The admission date is missing. | Details → |
| 186 | Per Diem This service is included in the In-patient Per Diem | Details → |
| 186 | Level of care change adjustment. Start: 06/30/2005 | Last Modified: 09/30/2007 | Details → |
| 186 | Denied. The provider has already been paid for this service under his individual L&I … | Details → |
| 187 | Obs Rate This service is included in the Observation Rate | Details → |
| 187 | Consumer Spending Account payments (includes but is not limited to Flexible Spending … | Details → |
| 187 | Denied. The clinic has already been paid for this service under the clinic's L&I prov… | Details → |
| 188 | Package This service is included in the Package Price | Details → |
| 188 | This product/procedure is only covered when used according to FDA recommendations. S… | Details → |
| 188 | Denied. Second diagnosis denotes a non-industrial condition or is not sufficiently sp… | Details → |
| 189 | Stoploss This service is included in the Stop Loss Rate | Details → |
| 189 | 'Not otherwise classified' or 'unlisted' procedure code (CPT/HCPCS) was billed when t… | Details → |
| 189 | Denied. Third diagnosis denotes a non-industrial condition or is not sufficiently spe… | Details → |
| 190 | Unequal Itemized Bill not equaled to charges | Details → |
| 190 | Payment is included in the allowance for a Skilled Nursing Facility (SNF) qualified s… | Details → |
| 190 | Denied. fourth diagnosis denotes a non-industrial condition or is not sufficiently sp… | Details → |
| 191 | Missing Anes Time Please rebill. The service is billed is missing Anesthesia Time Uni… | Details → |
| 191 | Not a work related injury/illness and thus not the liability of the workers' compensa… | Details → |
| 191 | Denied. Fifth diagnosis denotes a non-industrial condition or is not sufficiently spe… | Details → |
| 192 | Missing CPT MISSING CPT CODE | Details → |
| 192 | Non standard adjustment code from paper remittance. Usage: This code is to be used by… | Details → |
| 192 | Denied. Resubmit with list of ingredients, their cost and compounding time on Stateme… | Details → |
| 192 | Precertification/authorization/notification/pre-treatment absent Alert: You may appe… | Details → |
| 193 | Mult Proc MULTIPLE PROCEDURES BILLED WITHOUT MODIFIER | Details → |
| 193 | Original payment decision is being maintained. Upon review, it was determined that th… | Details → |
| 193 | Denied. The principal ICD diagnosis code is missing. | Details → |
| 194 | Mult Surg Multiple Surgery Reduction | Details → |
| 194 | Anesthesia performed by the operating physician, the assistant surgeon or the attendi… | Details → |
| 194 | Denied. Authorization of this service has been denied in this claim. | Details → |
| 195 | Non Par Timely NON PAR PROVIDER TIMELY FILING | Details → |
| 195 | Refund issued to an erroneous priority payer for this claim/service. Start: 02/28/20… | Details → |
| 195 | Denied. Principal diagnosis has not been accepted as related to this injury. | Details → |
| 196 | Not Quest Lab NON QUEST LAB PROVIDER | Details → |
| 196 | Claim/service denied based on prior payer's coverage determination. Start: 06/30/200… | Details → |
| 196 | Denied. Second diagnosis has not been accepted as related to this injury. | Details → |
| 197 | Convenience Patient convenience items are not covered under this benefit plan. | Details → |
| 197 | Precertification/authorization/notification/pre-treatment absent. Start: 10/31/2006 … | Details → |
| 197 | More specific revenue code needed. Use revenue code 291 for purchase or 292 for renta… | Details → |
| 198 | Rebill REBILL USING MEDICARE G CODES | Details → |
| 198 | Precertification/notification/authorization/pre-treatment exceeded. Start: 10/31/200… | Details → |
| 198 | Denied. The date of surgery and/or surgical procedure code is missing. Send adjustmen… | Details → |
| 199 | Facility Payment Reimbursement for service is included in the payment made to the fac… | Details → |
| 199 | Revenue code and Procedure code do not match. Start: 10/31/2006 | Details → |
| 199 | Denied. One or more diagnosis codes in the 2nd through 9th fields are invalid. | Details → |
| 200 | HH Claims Resubmit HH Claims on UB Home Health Agencies are required to submit claims… | Details → |
| 200 | Expenses incurred during lapse in coverage Start: 10/31/2006 | Details → |
| 200 | Denied. Principal and 2nd diagnosis codes not accepted as related to this injury. | Details → |
| 201 | Self Admin Self administered drugs are not covered services under this plan. | Details → |
| 201 | Patient is responsible for amount of this claim/service through 'set aside arrangemen… | Details → |
| 201 | L&I is processing these services under a new ICN. | Details → |
| 202 | SNF Exhaustted SKILLED NURSING DAYS EXHAUSTED | Details → |
| 202 | Non-covered personal comfort or convenience services. Start: 02/28/2007 | Last Modif… | 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.