Reviewed Sep 20, 2026 · maintained by Erin Rose · general reference, not legal advice
What the remit says
CO-97 — “The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated.”
Usually with: M15 “Separately billed services/tests have been bundled as they are considered components of the same procedure. Separate payment is not allowed”.
Verbatim, X12 code lists 11/1/2025.
Why it lands on drug claims
CPT allows one initial administration code per encounter; everything else that day is an add-on (96361, 96366, 96367, 96375, 96415, 96417). NCCI enforces that with column-1/column-2 pairs on the initial codes, all with modifier indicator 1, so a claim carrying two initial codes pays the column-1 line and returns CO-97 on the column-2 line. The remark is usually M15.
The trap is that the code that would have paid is not on the claim. A 45-minute post-infusion hydration is reportable — as 96361, the add-on hour, not 96360. Appealing the 96360 denial gets you nowhere; correcting the claim to 96361 gets you paid.
The rare legitimate two-initial-code day — two venous access sites, or the patient left and came back — is what the modifier indicator is for. XS (separate structure) or XE (separate encounter) on the column-2 line, with the nursing note that shows it, reopens the edit.
The NCCI pairs behind this denial
| Column 1 (pays) | Column 2 (denies) | Modifier opens it (practitioner) | Edit since | Modifier opens it (facility) |
|---|---|---|---|---|
| 96365 therapeutic IV infusion, initial hour | 96360 hydration, initial | Yes (indicator 1) | 01/2009 | Yes |
| 96413 chemo IV infusion, initial hour | 96365 therapeutic IV infusion, initial hour | Yes (indicator 1) | 01/2009 | Yes |
| 96413 chemo IV infusion, initial hour | 96374 IV push, single or initial | Yes (indicator 1) | 01/2009 | Yes |
CMS NCCI procedure-to-procedure edits, practitioner and hospital outpatient tables, Q3 2026. The modifier belongs on the column-2 line.
The fix
- Read the remit for which line carried CO-97 and which line paid; the paid line is the column-1 code.
- If the denied line is a second initial code (96360, 96365, 96374, 96409, 96413), recode it to the matching add-on and resubmit as a corrected claim (frequency code 7), not an appeal.
- Only if two initial services were genuinely separate: add XS or XE to the column-2 line and attach the note showing the second site or the second encounter time.
- Check the units on the add-on: 96361 and 96366 are per additional hour, and the MUE is per date of service.
What to attach
- The infusion flowsheet with start and stop times for each substance
- The order for the second service with its own clinical reason (dehydration, hypotension, a second drug)
- For XS/XE: documentation of the second access site or the second encounter
Corrected claim or appeal?
A corrected claim, almost always. The second initial code becomes its add-on (96361, 96366, 96367, 96375) and goes back as frequency 7. An appeal is only for the two-site or two-encounter day, with XS/XE already on the line and the flowsheet attached.
Medicare windows (redetermination 120 days, reconsideration 180 days, ALJ 60 days) and the commercial path are on the denials hub, cited to 42 CFR Part 405 Subpart I; the edits are CMS's NCCI tables.
Frequently asked
- CO-97 hit my 96365 and the payer paid 96413. Which is wrong?
- Neither code is wrong on its own; the pair is. On a chemo day the biologic or supportive infusion is reported as 96367 (sequential) or 96368 (concurrent), not 96365. Recode and resubmit as a corrected claim.
- The hydration ran the whole time the drug was infusing. Can I appeal the CO-97?
- No. Hydration concurrent with a drug infusion is not separately reportable under NCCI chapter XI, and fluid used to deliver the drug is incidental. The CO-97 is correct; drop the line.
- Does modifier 59 still open the 96365/96360 edit?
- On Medicare, yes, but XS or XE is the specific modifier and the one contractors look for. Some commercial payers reject 59 on these pairs outright. Use the X modifier that describes why the services were separate.
Related references
Put the add-on on the claim before the payer folds it
Claim Check applies the initial/add-on hierarchy and the NCCI pairs to the administration lines as you build the visit, so 96361 goes out instead of a 96360 that will bundle.
Open Claim CheckSources & how this is maintained
- Computed on this page
- NCCI PTP pair rows for the three initial-code pairs (modifier indicator and effective date, both tables). Edits vintage Q3 2026.
- Authored
- Why the second initial code folds, when XS/XE is honest, and the recode that pays.
- Corrections
- Send one with the remit line.