CARC 107 Active

CO-107: Related or Qualifying Service Not Identified

TL;DR

Your claim is missing the link to the related service. Find the original claim number or authorization reference, add it, and resubmit. This is a correctable data error, not an appeal situation.

Action

Resubmit

Who Pays

Provider

Appeal

Patient Impact

None

Disclaimer

This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does CO-107 Mean?

CO-107 is a contractual adjustment indicating the provider submitted a claim without the required linking information to connect it to a related or qualifying service. The provider is responsible for including this data, and the denied amount is a contractual write-off until the claim is corrected and resubmitted. The patient cannot be billed for this provider-side submission error.

CARC 107 fires when a payer's system cannot locate the connection between the submitted claim and a related or qualifying service it depends on. Every dependent service — follow-up visits, post-operative care, secondary procedures tied to an initial qualifying claim — requires a reference linking it back to the original. When that reference is missing or incorrect, the payer cannot validate the relationship and denies the claim.

This is fundamentally a data completeness issue, not a coverage dispute. The service itself may be perfectly valid, but the claim lacks the linking information the payer needs to process it. The 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF) often contains specific guidance about what reference is required. Common missing elements include original claim ICN numbers, prior authorization references, or qualifying procedure identifiers.

CO is the dominant group code for CARC 107 because the missing linking data is the provider's responsibility to include. The resolution is straightforward: identify the correct reference, add it to the claim, and resubmit. This is not a denial that requires an appeal — it requires a data correction.

Common Causes

Cause	Frequency
Missing related claim or service reference number The claim was submitted without the original claim number, prior authorization number, or other reference identifier that links this service to a previously submitted qualifying claim or procedure	Most Common
Incorrect or missing 835 Healthcare Policy Identification Segment The 835 loop 2110 Service Payment Information REF segment that provides linking data between related services was absent or contained incorrect reference information	Most Common
Dependent service billed without primary procedure reference A follow-up service, post-operative visit, or bundled service was submitted without properly identifying the initial procedure or qualifying claim it depends on, such as pre-op visits or follow-up care tied to an initial procedure	Common
Coding errors in service linkage fields Incorrect procedure or diagnosis codes were used that prevent the payer's system from automatically linking the current service to the related qualifying claim	Common
Payer policy changes not implemented in billing system The payer updated their requirements for linking related services but the provider's billing system was not updated to include the new required fields or reference formats	Occasional
Poor interdepartmental communication The clinical department performed a dependent service but did not communicate the original qualifying claim details to the billing department, resulting in incomplete claim submission	Occasional

How to Resolve

Locate the missing related claim or service reference, add it to the claim, and resubmit with complete linking information.

Check the 835 segment for guidance Review the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF) on the remittance to identify exactly what linking reference the payer requires.
Look up the original claim Search your billing system for the original qualifying claim this service depends on. Locate the ICN (Internal Control Number), prior authorization number, or original claim reference.
Add the linking data Update the claim with the correct related claim/service identification. Ensure the reference number, date of service, and procedure codes for the qualifying service are accurate.
Resubmit with complete information Submit the corrected claim with all linking fields populated within the filing deadline. Flag the resubmission for follow-up to confirm acceptance.

Do Not Appeal This Code

CO-107 indicates missing linking information on the claim, which is a correctable submission error. Add the required related claim or service reference number and resubmit. Appeals are not the appropriate path for missing data corrections.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-107:

RARC	Description
N522	Missing or invalid related claim/service identification Add the original claim number or prior authorization reference and resubmit →
M76	Missing or incomplete information needed to link this service to the related claim Review 835 Healthcare Policy Identification Segment for required linking fields →

How to Prevent CO-107

Implement claim scrubbing rules that flag claims for dependent services (follow-ups, post-op visits, related procedures) when the original claim reference is missing
Establish billing workflows that automatically pull the original claim number when scheduling follow-up or dependent services
Train billing staff on payer-specific requirements for linking related claims, including the proper format for reference numbers and authorization identifiers
Conduct regular audits of CARC 107 denials to identify patterns by payer or service type that indicate systemic linking gaps
Maintain communication channels between clinical scheduling and billing to ensure qualifying claim details are transferred for dependent services
Stay current with payer policy updates on claim linkage requirements and update billing templates accordingly

General Prevention

Implement claim scrubbing software that flags missing related claim references before submission, particularly for dependent services like follow-ups and post-operative visits
Double-check all claim linking fields before submission, ensuring original claim numbers and prior authorization references are included for dependent services
Establish clear workflows between clinical and billing departments to communicate qualifying claim details when scheduling dependent or follow-up services
Conduct regular staff training on payer-specific requirements for linking related services, including proper use of the 835 Healthcare Policy Identification Segment
Perform internal audits to identify CARC 107 denial patterns by payer and service type, addressing systemic linking issues before they accumulate
Stay current with payer policy updates regarding claim linkage requirements and update billing system templates accordingly

Also Filed As

The same CARC 107 may appear with different Group Codes:

OA-107

Related Denial Codes

CO-13 — Date of Death Precedes Date of Service CO-14 — Date of Birth Follows Date of Service CO-16 — Missing Information or Billing Error CO-31 — Patient Not Identified as Insured CO-112 — Service Not Furnished Directly or Not Documented

Sources

https://www.mdclarity.com/denial-code/107
https://billingfreedom.com/list-of-common-denial-codes-and-their-reasons/
https://docs.claim.md/docs/claim-adjustment-reason-codes
Codes maintained by X12. Visit x12.org for official definitions.