CARC Code

231

🔴 Hard Denial

Mutually Exclusive Procedures Same Day

Two or more procedures were billed together on the same day that cannot be performed at the same time according to coding rules. The payer's system identified these procedures as incompatible when billed together.

coding
Resolution: 35%Hard difficulty21-45 days avg

How to resolve this denial

Review NCCI edits; rebill the appropriate procedure or appeal with clinical documentation

  1. 1

    Review NCCI edits for the billed procedure combination

  2. 2

    Determine if a modifier is applicable to bypass the bundling edit (e.g., -59, XE, XS, XP, XU)

  3. 3

    Verify the procedures were performed independently and at separate sites/times

  4. 4

    If modifier is appropriate, resubmit with the correct modifier and documentation

  5. 5

    If bundled correctly, accept the reduction and adjust the claim balance

Resolve this denial →
✓ Pre-action checklist — verify before contacting the payer
  1. Review the full remittance advice (ERA/EOB) for additional RARC codes that explain the denial.

  2. Verify the claim was submitted with correct patient eligibility and benefit information.

  3. Check if this denial applies to a specific line item or the entire claim.

More about CO-231 — stats, related codes, appeal template

35%

Recovery Rate

21-45 days

Avg. Resolution

Hard

Difficulty

Occasional

Frequency

Payer-Specific Notes

How major payers handle CARC 231 by specialty.

Blue Cross Blue Shield

BCBS requires appeal submission within 180 days for most plans.

Appeal Letter Template

Generic appeal template for CARC 231 denials.

We are submitting a formal appeal for claim [CLAIM_NUMBER] for patient [PATIENT_NAME], date of service [DOS]. This claim was denied/adjusted with CARC 231 indicating: "Mutually exclusive procedures cannot be done in the same timeframe.." We have reviewed the claim and are providing the attached documentation to support reconsideration. [SUPPORTING_DOCUMENTATION]. Please reconsider payment per the terms of our contract.

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