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CO-97 Denial Code: Bundled Into Another Service

CO-97 means the payer bundled this service into another one: its benefit is included in the payment for a different service or procedure that was already adjudicated. Under CO the amount is a provider write-off unless the service was truly separate and you can support unbundling.

Quick facts

Code
CO-97 (CARC 97)
Status
Active In use since January 1, 1995; last modified July 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The bundled amount is the provider's responsibility. It cannot be billed to the patient.
  • OA (Other Adjustment): Occasionally used when the bundling is informational, such as a component reported only for tracking. There is usually no balance to collect.
Official description
The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated. Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-97 means

CARC 97 means the benefit for this service is included in the payment or allowance for another service that has already been adjudicated. In plain terms, the service was bundled. The payer considers it part of something else it already paid, so it pays nothing extra for it.

Bundling comes from several sources:

  • NCCI procedure-to-procedure (PTP) edits, used by Medicare, Medicaid, and many commercial payers.
  • Global surgery rules, where pre-operative, intra-operative, and routine post-operative care is included in the surgical payment.
  • Payer-specific bundling policies that go beyond NCCI.

The 835 may include a policy reference (loop 2110 REF) naming the policy used. Example: a practice bills a procedure and a minor related service on the same day. The payer pays the procedure and reports CO-97 on the second line because the edit treats it as integral to the first.

Common causes

  • Two services billed on the same date form an NCCI column 1/column 2 pair and no modifier indicated they were distinct.
  • A modifier was used, but the edit does not allow modifiers (modifier indicator 0).
  • An E/M service on the same day as a minor procedure without modifier 25, or with modifier 25 but without documentation of a significant, separately identifiable service.
  • Follow-up care billed during a global surgical period without modifier 24, 79, or 58 when one applied.
  • Supplies or services the payer considers integral to the main procedure were billed separately.
  • Claims for the same patient and date split across different claims, so the bundled line was adjudicated after the primary service was paid.

How to fix it

  1. Identify the primary service. Find which line or earlier claim absorbed the payment, and check the remark code for the reason (M15, N19, N20, M144, and similar).
  2. Check the edit. Look up the pair in the NCCI PTP tables or the payer’s policy, including whether a modifier is allowed.
  3. If the service was distinct and documented, submit a corrected claim (resubmission code 7 in box 22) with the right modifier in box 24D: 59 or XE, XS, XP, XU for distinct services, 25 for a separate E/M, 24, 58, or 79 for global period exceptions. Some payers want a reconsideration instead; follow their process.
  4. If the payer ignored a correct modifier, appeal with operative notes or visit documentation that shows the separate site, session, or problem.
  5. If the bundling is correct, post CO-97 as a contractual adjustment. Do not rebill the line and do not bill the patient.

For a deeper walk-through, see our guide to NCCI denials, PTP bundling, and modifiers.

How to prevent it

  • Check NCCI and payer bundling edits before submission, especially for same-day procedure combinations. A Claims Validator can flag PTP pairs and missing modifiers.
  • Train providers to document what makes a second service distinct: separate site, separate session, separate problem.
  • Track global periods so post-operative visits carry the right modifier or are not billed at all.
  • Bill all services for the same patient and date on one claim when possible so the payer adjudicates them together.
  • Audit modifier 59 and 25 use periodically. Overuse attracts payer review.

Specialty notes

PT/OT practices commonly see CO-97 on timed therapy codes paired with evaluation or manual therapy services where NCCI edits apply; modifier 59 is appropriate only when the services were performed in separate, distinct intervals and documented that way. In behavioral health, psychotherapy add-on codes billed with an E/M service require the E/M to be separately documented, or the add-on may be bundled.

Remark codes that may appear with CO-97

  • M15 (Separately billed services/tests have been bundled as they are considered components of the same procedure.): Separately billed services were bundled as components of the same procedure.
  • N19 (Procedure code incidental to primary procedure.): The procedure is incidental to the primary procedure.
  • N20 (Service not payable with other service rendered on the same date.): Not payable with another service rendered on the same date.
  • M144 (Pre-/post-operative care payment is included in the allowance for the surgery/procedure.): Pre- or post-operative care is included in the surgical allowance, a global period issue.
  • N525 (These services are not covered when performed within the global period of another service.): Not covered because it falls within the global period of another service.
  • CO-234 (This procedure is not paid separately.): The procedure is not paid separately; often used for policy-based packaging rather than NCCI edits.
  • CO-236 (This procedure or procedure/modifier combination is not compatible with another procedure or procedure/modifier combination provided on the same day…): The procedure or modifier combination is not compatible with another procedure on the same day under NCCI or payer policy.
  • CO-231 (Mutually exclusive procedures cannot be done in the same day/setting.): Mutually exclusive procedures that cannot be done on the same day.
  • CO-59 (Processed based on multiple or concurrent procedure rules. (For example multiple surgery or diagnostic imaging, concurrent anesthesia.)): Reduced under multiple or concurrent procedure rules rather than bundled away entirely.
  • CO-B15 (This service/procedure requires that a qualifying service/procedure be received and covered.): The service requires a qualifying service that was not paid or identified.

CO-97 FAQ

Can I resubmit a CO-97 claim with modifier 59?

Only if the service was genuinely distinct, for example a different session, different anatomic site, or separate incision, and your documentation shows it. Adding modifier 59 or an X modifier just to bypass an edit is a compliance risk.

Can I bill the patient for a CO-97 amount?

No. Bundled amounts under CO are provider responsibility, and the patient has already received the benefit through the primary service's payment.

Is CO-97 always an NCCI edit?

Not always. It covers NCCI procedure-to-procedure edits, global surgery rules, and payer-specific bundling policies. The remark code and policy reference tell you which one applied.

How is CO-97 different from CO-236?

CO-97 says this service's payment is included in another service's payment. CO-236 says the procedure or modifier combination is not compatible with another procedure on the same day. Both are bundling-related, and payers vary in which they use.