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Claim adjustment reason code

CO-97: Included in the payment for another service

CO-97 means: The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated. The payer is bundling this code into another one on the same claim. Sometimes that is correct and sometimes it is not.

Read the group code before you act on this

97 is the claim adjustment reason code. The CO in front of it is the group code — a separate field the payer sets on the remittance. The same reason code arrives under different group codes depending on the payer and the situation, and the group code, not the reason code, decides who owes the money.

CO — contractual obligation. You write it off. You may not bill the patient.
PR — patient responsibility. Billable to the patient.
OA — other adjustment, and PI — payer initiated reduction. Neither is patient responsibility.

What causes it

A genuine NCCI bundling edit where the codes should not be billed together
A separately identifiable service billed without modifier 25 or modifier 59
A global surgical period the payer believes is still running
An unrelated service performed on the same day as a procedure

How to work it

Check the NCCI edit pair and whether a modifier is permitted to break it — some pairs allow it and some do not, and billing a modifier on a pair that does not allow one is a compliance problem, not a shortcut
Where modifier 25 applies, the documentation must show a separately identifiable evaluation, not just the same visit described twice
For global period denials, confirm the surgery date and whether the service was related. Modifier 24 or 79 may apply
Appeal with the operative note or the visit note, not with a letter asserting the codes are different

How to stop it recurring

This is where coding knowledge pays for itself. The wrong answer costs the claim, and the wrong shortcut costs more than that.

Who does this work

A medical coding seat at $2,500 per seat per month works this queue full time, during your business hours, inside your own system. Every call is logged with the payer reference number and the outcome, and every Friday you get it in writing.

What that seat does →

Codes worked the same way

CO-97 is checked against the contract before any work is done. So are these, which is why a queue sorted by recovery route moves faster than one sorted by code number — the same person, in the same system, with the same evidence to hand, clears all of them in one pass.

CO-45 — Charge exceeds the fee schedule
CO-18 — Exact duplicate claim or service
CO-288 — Referral absent
PR-204 — Not covered by this plan
OA-23 — Prior payer already adjudicated
CO-286 — Appeal filed too late

Specialties that name this among their costliest

These are specialties whose own worst denials include one of this kind. The line under each is the denial they name, quoted from their page so you can see what the link is based on.

Anesthesia
Post-op pain blocks bundled into the anesthesia claim
Ophthalmology
Retinal imaging and fundus photography done at the same visit, with one line denied as bundled because the record never gives a separate reason for each test.
Otolaryngology
The operative note does not state which sinuses were entered on which side, so the sinus surgery lines are bundled together or only one side is allowed.
Urgent Care
A global urgent care case rate billed alongside a separate evaluation and management line where the contract pays one or the other, and the second line drops off
Primary Care
A preventive visit and a same-day problem visit written up in one undivided note, so the problem visit bundles into the wellness visit and is not paid separately.
Oncology
Payer required the drug through its contracted specialty pharmacy, the practice infused from its own stock, and the buy-and-bill claim was denied in full.

What leaving it costs

Working a denied claim costs $57.23 per denied claim in administrative time. Source. At 100 denials a month — an illustration, not a measurement of your practice — that is $5,723 a month, or $68,676 a year, in labour alone.

The figure that makes it worth spending: about 90% of initially denied claims are eventually paid. Source. The reason a denial sits is almost never that nobody knows how to work it — it is that nobody has the hours.

Questions

What does denial code CO-97 mean?

The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated. In plain terms: The payer is bundling this code into another one on the same claim. Sometimes that is correct and sometimes it is not.

What causes CO-97?

A genuine NCCI bundling edit where the codes should not be billed together. A separately identifiable service billed without modifier 25 or modifier 59. A global surgical period the payer believes is still running. An unrelated service performed on the same day as a procedure.

How do you fix a CO-97 denial?

Check the NCCI edit pair and whether a modifier is permitted to break it — some pairs allow it and some do not, and billing a modifier on a pair that does not allow one is a compliance problem, not a shortcut. Where modifier 25 applies, the documentation must show a separately identifiable evaluation, not just the same visit described twice. For global period denials, confirm the surgery date and whether the service was related. Modifier 24 or 79 may apply. Appeal with the operative note or the visit note, not with a letter asserting the codes are different.

Can CO-97 be prevented?

This is where coding knowledge pays for itself. The wrong answer costs the claim, and the wrong shortcut costs more than that.

Is CO-97 the same as PR-97?

Same reason, different group code. The number 97 is the reason: The payer is bundling this code into another one on the same claim. Sometimes that is correct and sometimes it is not. The prefix says who carries the amount. CO means contractual obligation — the payer says the amount is not billable to anybody, and it is written off unless the denial itself is overturned. PR-97 is the same reason assigned to patient responsibility — the payer says the amount is owed by the patient, and it is billed to them. Read the prefix before the number: it decides whether you appeal, write off, or bill the patient.

What is the difference between CO-97 and CO-96?

CO-97: The payer is bundling this code into another one on the same claim. Sometimes that is correct and sometimes it is not. CO-96: The plan does not cover this service at all. Distinct from medical necessity, which is an argument about evidence. They are different reasons that happen to sit next to each other in the list, and they are worked differently — CO-97 is checked against the contract before any work is done; CO-96 is appealed with clinical documentation.

Code descriptions are the standard X12 claim adjustment reason and remittance advice remark code text. Payer policies differ, and the payer’s own coverage policy governs any individual claim. This page is working guidance, not legal or clinical advice.

Last updated 2026-09-12. This is operational guidance drawn from payer remittance practice, not legal, coding or reimbursement advice. Payer-specific rules vary and change; confirm against the payer’s own policy before acting on a specific claim.

Written by Ibtesam Asif · Last reviewed 2026-09-12

Code descriptions are the standard published text. Everything after them is operational guidance from our own work, and payer policy governs any individual claim.

Other denial codes

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