231Denial Code (CARC)Active
CO 231 Denial Code - Fix Mutually Exclusive Procedures
Code 231 means that two procedures billed together are considered mutually exclusive, and cannot be performed on the same day or in the same setting. This adjustment indicates that the payer has denied payment for one of the procedures due to this policy.
Who Pays: Group Code Liability
For code 231, the liability typically falls under CO, meaning it's a contractual write-off and the patient should not be billed for the denied procedure.
Why Claims Get Code 231
- Billing two procedures that are clinically incompatible to perform together.
- Submitting claims for procedures that the payer's policy considers redundant when done on the same day.
- Failure to follow payer guidelines regarding procedure combinations.
- Coding errors that inaccurately pair exclusive procedures.
- Lack of awareness of payer-specific mutually exclusive procedure lists.
How to Fix & Resubmit
- Verify which procedure is denied by checking the 835 Healthcare Policy Identification Segment.
- Review the clinical documentation to confirm if both procedures were indeed performed together.
- Consult the payer's policy on mutually exclusive procedures to understand why the denial occurred.
- If the combination was billed in error, submit a corrected claim with the appropriate procedure.
- If the denial is incorrect based on clinical necessity, prepare a formal appeal with supporting documentation.
Corrected Claim or Appeal?
Submit a corrected claim if the procedures were mistakenly billed together. If the procedures are clinically justified, a formal appeal with medical records may be necessary.
Preventing Future 231 Denials
- Regularly update and consult the payer's list of mutually exclusive procedures.
- Educate coding staff on common procedure pairs that trigger code 231.
- Implement a pre-submission audit to catch mutually exclusive billing errors.
- Establish clear guidelines for billing procedures performed on the same day.