CO-182: Procedure Modifier Invalid on Date of Service
Correct the modifier to one that was valid on the date of service and resubmit. Do not appeal.
What Does CO-182 Mean?
With CO (Contractual Obligation), the invalid modifier is the provider's responsibility to correct. Identify the proper replacement modifier and resubmit the claim. This is a straightforward coding correction that does not require an appeal.
CARC 182 indicates that a modifier appended to a procedure code on the claim was either expired, not yet effective, or otherwise invalid for the date of service. Modifiers provide additional information about how or where a service was performed, and like procedure codes, they have defined validity periods.
This denial commonly occurs after annual coding updates when modifiers are retired or replaced, when billing systems are not updated with current modifier tables, or when an incorrect modifier is applied due to a data entry error. The resolution is to identify the correct modifier and resubmit the claim.
Common Causes
| Cause | Frequency |
|---|---|
| Modifier expired or retired before date of service The procedure modifier used on the claim was retired or no longer valid before the date the service was rendered | Most Common |
| Incorrect modifier used for the procedure The modifier appended to the procedure code is not valid for that specific code or does not apply to the circumstances of the service | Most Common |
| Modifier not yet effective on date of service The modifier has a future effective date and was not valid on the date the service was performed | Common |
| Typographical error in modifier A data entry error resulted in an invalid modifier being submitted on the claim | Common |
| Billing system not updated with modifier changes The provider's billing system was not updated with the latest modifier changes, resulting in use of outdated modifiers | Common |
How to Resolve
- Check the modifier's validity dates Verify the modifier's effective and termination dates against the date of service.
- Identify the correct modifier Determine the appropriate modifier based on the service circumstances and current coding guidelines.
- Resubmit with the correct modifier Update the claim and resubmit.
- Update modifier tables Ensure your billing system has current modifier tables to prevent future denials.
This denial indicates the modifier was not valid on the date of service. Correct the modifier and resubmit the claim rather than appealing.
Common RARC Pairings
The RARC code tells you exactly what triggered the CO-182:
| RARC | Description |
|---|---|
| M20 | Missing/incomplete/invalid HCPCS modifier Verify the modifier is valid for the procedure code and date of service, then resubmit → |
| N130 | You may need to review plan documents or guidelines Review current modifier listings for valid replacements → |
How to Prevent CO-182
- Update billing system modifier tables when annual updates are released
- Use claim scrubbing tools that validate modifiers against procedure codes and dates of service
- Train coding staff on proper modifier usage and effective dates
- Verify modifier validity before claim submission, especially for less commonly used modifiers
- Maintain a reference of recently changed or retired modifiers
Also Filed As
The same CARC 182 may appear with different Group Codes:
Related Denial Codes
Sources
- https://www.mdclarity.com/denial-code/182
- https://x12.org/codes/claim-adjustment-reason-codes
- https://portal.ct.gov/-/media/ohs/health-it-advisory-council/apcd-advisory-group/data-submission-guide-workgroup/meeting-materials/6-30-22/carc-codes_final.pdf
- https://medicaid-documents.dhhs.utah.gov/Documents/pdfs/ClaimDenialCodes.pdf
- Codes maintained by X12. Visit x12.org for official definitions.