CO-198: Precertification/Authorization Limits Exceeded
Services exceeded the authorized limit. Appeal with clinical documentation or request a retrospective authorization extension.
What Does CO-198 Mean?
With CO (Contractual Obligation), the excess services are the provider's contractual responsibility. The provider cannot transfer this cost to the patient. Appeal with clinical documentation supporting medical necessity for the additional services beyond the authorized limit.
CARC 198 indicates that while a prior authorization was obtained, the services billed exceed the scope of that authorization. The provider may have delivered more visits or units than authorized, continued treatment beyond the approved date range, or prescribed a medication quantity that exceeds the approved amount.
Unlike CARC 197 (no authorization at all), CARC 198 means authorization existed but was exhausted or exceeded. This is common in therapy practices where patients use all their authorized visits, in ongoing treatment programs that extend beyond the approved duration, and in medication management where dosage or quantity changes were not reflected in an updated authorization.
Common Causes
| Cause | Frequency |
|---|---|
| Authorized visit or unit count exceeded The provider delivered more visits, sessions, or units than the payer authorized, and the excess services are denied under the contractual obligation | Most Common |
| Authorization expired before service was rendered The authorization had a validity period that expired before all services were completed, and the provider continued treatment without obtaining a new or extended authorization | Most Common |
| Treatment duration exceeded approved scope The treatment plan extended beyond the approved duration without obtaining reauthorization from the payer | Common |
| Medication quantity exceeded authorized amount The prescribed medication quantity or dosage exceeds what was pre-approved by the payer | Common |
| Failure to request authorization extension The provider did not submit a request for extended or additional authorization before the current authorization limit was reached | Common |
| Services billed beyond variance allowance In workers compensation cases, the treatment provided is not consistent with the approved variance or treatment plan | Occasional |
How to Resolve
- Identify the exceeded limit Determine which specific authorization limit was exceeded — visits, units, dates, or medication quantity.
- Compile medical necessity documentation Gather physician notes, clinical assessments, and treatment records supporting the need for additional services.
- Request retrospective authorization Submit a request for additional authorized services with medical necessity documentation.
- Appeal the denial File an appeal with clinical justification, referencing applicable coverage policies and plan language.
Appeal with documentation of medical necessity and clinical justification. Include physician notes, prior authorization records if applicable, and any relevant coverage policies that support the service. Reference the specific plan language or LCD/NCD that covers the service. For Medicare, file the redetermination within 120 days.
Common RARC Pairings
The RARC code tells you exactly what triggered the CO-198:
| RARC | Description |
|---|---|
| N386 | This decision was based on a National Coverage Determination (NCD) or Local Coverage Determination (LCD). Review the applicable NCD or LCD for specific coverage guidelines and authorization limits → |
| N130 | Consult plan benefit documents/guidelines for coverage of this service. Review the patient plan benefits and guidelines for coverage limitations on this service → |
| N362 | The number of Days or Units of Service Exceeds our acceptable maximum. Verify the number of days or units billed does not exceed the payer maximum and request extension if needed → |
How to Prevent CO-198
- Track authorization utilization actively and set alerts when approaching the authorized visit or unit limit
- Submit reauthorization requests well before the current authorization expires or is exhausted
- Implement automated authorization tracking in your practice management system that flags claims approaching authorization limits
- Review the authorization details (dates, units, CPT codes) before each service delivery to ensure the visit is still within scope
- Maintain a centralized authorization log accessible to scheduling, clinical, and billing staff
- Train clinical staff to document ongoing medical necessity at each visit to support future reauthorization requests
Also Filed As
The same CARC 198 may appear with different Group Codes:
Related Denial Codes
Sources
- https://x12.org/codes/claim-adjustment-reason-codes
- https://www.mdclarity.com/denial-code/198
- https://www.wcb.ny.gov/CMS-1500/WCB-CARC-RARC-codes.pdf
- https://www.aapc.com/resources/claim-adjustment-reason-codes
- Codes maintained by X12. Visit x12.org for official definitions.