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CO-249 Denial Code: Claim Identified as a Readmission

CO-249 means the payer identified this claim as a readmission. It links the stay to an earlier admission, often within a set number of days, and denies or combines payment under its readmission policy. X12 allows CARC 249 only with group code CO.

Quick facts

Code
CO-249 (CARC 249)
Status
Active In use since September 30, 2012.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): X12 restricts CARC 249 to the CO group. The facility bears the adjustment and cannot bill the patient for it.
Official description
This claim has been identified as a readmission. (Use only with Group Code CO)
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-249 means

CARC 249 says this claim has been identified as a readmission, and X12 restricts it to group code CO. The payer compared the admission with the patient’s recent history, found an earlier inpatient stay within its readmission window, and decided not to pay the second stay separately.

Payers take different approaches. Some deny the readmission outright, some combine the two stays into one payment, and some apply a reduction only when the readmission is related to the first stay or considered preventable. The code does not say which approach was used, so read the remark codes and the payer’s readmission policy.

Example: a patient is discharged, then readmitted a few days later with a complication of the same condition. Under a payer policy that combines related readmissions within its window, the second claim comes back CO-249, and the facility may need to submit a combined claim covering both stays.

Common causes

  • Related readmission inside the payer’s defined window.
  • Planned readmission (such as staged surgery) not identified as planned on the claim.
  • Premature discharge findings from payer review.
  • Transfer or leave of absence billed as a new admission rather than a continuation.
  • Unrelated condition matched as related because of overlapping diagnoses.

How to fix it

  1. Get the payer’s readmission policy and confirm the window and relatedness rules for this product.
  2. Compare the two stays: dates, principal diagnoses, and discharge plans.
  3. If the readmission was planned or unrelated, appeal with records showing the distinct reason. Make sure planned readmissions carry the right discharge status and condition codes.
  4. If the payer requires a combined claim, submit it as instructed, often by adjusting the original claim to include both stays.
  5. If the finding is correct, post the adjustment. Do not bill the patient.

How to prevent it

  • Strengthen discharge planning and follow-up so patients are less likely to return.
  • Flag readmissions within the payer’s window at registration for case management and coding review.
  • Document planned readmissions clearly and use correct discharge status codes.
  • Track CO-249 by service line and payer; an ERA Analyzer can reveal where readmission denials cluster.

Remark codes that may appear with CO-249

  • N561 (The bundled claim originally submitted for this episode of care includes related readmissions.): In a bundled episode, related readmissions are included in the original claim, which you may need to resubmit.
  • N10 (Adjustment based on the findings of a review organization/professional consult/manual adjudication/medical advisor/dental advisor/peer review.): A review organization or payer medical review made the readmission determination.
  • CO-216 (Based on the findings of a review organization or the payer's findings.): Adjustment based on a review organization's or payer's findings.
  • CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Denied as not medically necessary, rather than as a readmission.
  • CO-233 (Services/charges related to the treatment of a hospital-acquired condition or preventable medical error.): Denied because the care relates to a hospital-acquired condition or preventable error.
  • CO-A8 (Ungroupable DRG.): The claim could not be grouped to a DRG.

CO-249 FAQ

What counts as a readmission?

It depends on the payer's policy: typically a return to the hospital within a set number of days of discharge, sometimes limited to related diagnoses or planned versus unplanned returns. Check the payer's readmission policy or contract.

Can I appeal a CO-249 readmission denial?

Yes, if the readmission was unrelated to the first stay, was planned, or falls outside the payer's policy. Provide records showing the clinical reason for the second admission.

Does Medicare deny readmissions with CO-249?

Medicare's Hospital Readmissions Reduction Program reduces payments at the hospital level rather than denying individual readmissions. Payers with claim-level readmission policies, including many commercial and Medicaid plans, are more likely to use CO-249.

Does CO-249 affect the physician's claim for the readmission?

Not directly. CARC 249 applies to the facility claim. Physicians billing professional services during the readmission are generally paid under their own claims unless a payer policy says otherwise.