CO-97 on a dental claim: bundled procedures, and when an appeal works
CO-97: The benefit for this service is included in the payment for another service already adjudicated. What it means on a dental claim, why dental offices get it, what to do, and whether the patient owes it.
By Dr. Salem Sayegh, general dentist, Glendora, California ·
The short answer: CO-97 means the payer considers the procedure part of another procedure it has already processed, so it pays nothing separately for it. On dental claims it usually comes from a core buildup billed with a crown, a pulp cap or desensitizer with a filling, or palliative treatment on the same visit as definitive treatment. An appeal works only when the documentation shows the procedure was genuinely separate.
| Code | CO-97 (adjustment reason code) |
|---|---|
| Group | CO, contractual obligation: the office absorbs it |
| Meaning | Bundled: the payer counts it as part of another procedure it already paid |
| Is it a denial? | Yes, for that line. The other procedure is usually paid |
| Bill the patient? | Usually not when in network; check your contract |
| Usually fixable? | Sometimes, with a narrative and images |
Why dental offices get CO-97
- Core buildup (D2950) billed with a crown, when the payer pays a buildup only if it is needed to retain the crown.
- Pulp cap (D3110 or D3120) on the same tooth and date as a restoration.
- Desensitizing medicament or resin on the same tooth as a restoration.
- Palliative treatment (D9110) on the same visit as definitive treatment.
- Individual periapical images taken close to a full-mouth series, or a limited exam on the same day as a comprehensive one.
What CO-97 looks like on an EOB
| Procedure | Billed | Allowed | Paid | Adjustments |
|---|---|---|---|---|
| D2740 (porcelain crown) | $1,400.00 | $950.00 | $475.00 | CO-45 $450.00, PR-2 $475.00 |
| D2950 (core buildup) | $325.00 | $0.00 | $0.00 | CO-97 $325.00 |
The crown is paid. The buildup is bundled into it, so the whole $325 is adjusted under CO-97.
What to do about CO-97
- Check which procedure the payer bundled it into. It is usually another line on the same claim or a claim from the same date.
- Read the payer’s policy for that pair. If the plan bundles the two in every case, an appeal will not succeed.
- If the procedure was clinically separate, for example a buildup needed because most of the coronal structure was missing, appeal with a narrative and the pre-operative radiograph or an intraoral photo.
- If you do not appeal, post the CO-97 amount as a write-off.
Can you bill the patient for CO-97?
Usually not, when you are in network. Most PPO contracts treat a bundled or disallowed procedure as included in the fee for the other one, so the patient cannot be charged separately. Some contracts and some states allow billing the patient for certain disallowed services, so check your contract before you do.
Questions about a specific EOB line?
Ask Sai Biller, our free dental insurance chatbot. Type the codes and amounts from the line, leave out patient details, and it explains what happened and what to do next. For offices posting every day, Sai for Dentists reads each EOB line as it posts, checks the allowed amount against your contracted fee and lists every denial, downgrade and underpayment for your team.
Sources
- X12 claim adjustment reason codes and remittance advice remark codes. Meanings here are paraphrased; see X12 for the official wording.
- American Dental Association, CDT: Code on Dental Procedures and Nomenclature. Procedure labels here are our own short descriptions.
- Payers apply these codes differently. Your contract and each payer’s provider manual decide what applies to your office.
Common questions
Why does medical billing advice about CO-97 not help on dental claims?
Most CO-97 advice online is about medical NCCI edits and modifier 59. Dental claims rarely use modifiers that way, so the fix on a dental claim is clinical documentation showing the procedure was separate, not a modifier.
Can I appeal a CO-97 on a core buildup?
Yes, if the buildup was needed to retain the crown. Send a narrative describing how much tooth structure was missing, with the pre-operative radiograph or an intraoral photo. If the plan never pays a buildup with a crown, the appeal will fail.
Is CO-97 the same as a downgrade?
No. CO-97 pays nothing for the line because it is included in another procedure. A downgrade pays the line at a cheaper procedure’s fee under an alternate benefit clause.
