A billing manager at a pain management practice noticed something odd in the second week of April. A pair of codes her physicians had billed together for years, with a modifier, started paying without the modifier. Another pair that had always paid started denying with CO-236. Nobody had changed anything in the office. What changed was the quarterly National Correct Coding Initiative file, and her clearinghouse had loaded the new edits the day they took effect.
The NCCI edits April 2026 release, version 32.1, took effect April 1, 2026. CMS posted the files in late March. It is one of the larger quarterly updates by count, with more than 3,750 new procedure-to-procedure pairs, more than 4,800 deleted pairs, six revised pairs and 121 new medically unlikely edits. Most of the volume is concentrated in Category III codes and the medicine section, so for many practices the net effect is small. For a few it is not.
This is what the update contains, how to read the files if you have never opened one, and how we reconcile a quarterly update against a practice's actual billing.
Key takeaways
- NCCI version 32.1 is effective for dates of service on and after April 1, 2026; claims for March dates are edited against version 32.0.
- Deleted pairs outnumber new pairs this quarter, which means some code combinations that used to require a modifier no longer do, and some that used to bundle now pay separately.
- The MUE change most primary care practices will notice is G0447 (behavioral counseling for obesity) dropping from two units to one unit per date of service.
- Commercial payers adopt NCCI on their own timelines, so a claim can pass Medicare edits and fail a commercial payer's older version for several weeks.
What NCCI is, briefly
A glossary line for the physicians reading: the National Correct Coding Initiative is the set of automated edits Medicare uses to prevent payment for code combinations that should not be billed together, or for more units of a service than is clinically plausible. It has three parts. Procedure-to-procedure (PTP) edits list pairs of codes where the column 2 code is considered part of the column 1 code on the same day. Medically unlikely edits (MUEs) set the maximum units of a code one patient can receive on one date. Add-on code edits list which primary codes an add-on code may accompany.
Each PTP pair carries a modifier indicator. Indicator 0 means the pair can never be unbundled; billing both produces a denial of the column 2 code regardless of modifiers. Indicator 1 means a modifier such as 59, XS, XU or 25 can override the edit when the circumstances justify it and the documentation supports it. Indicator 9 means the edit was deleted. When the manager's code pair started paying without a modifier, its edit had been deleted; when the other pair started denying, a new edit with indicator 0 had been created.
CMS updates the edits quarterly, effective January 1, April 1, July 1 and October 1, and publishes the files on the NCCI pages of the CMS website about a month before. The version number tracks the year (32 corresponds to 2026) and the quarter.
NCCI edits April 2026: what changed in version 32.1
| Component | April 2026 change | Practical meaning |
|---|---|---|
| New PTP pairs | More than 3,750 | New combinations that now bundle; concentrated in Category III (T) codes and medicine codes |
| Deleted PTP pairs | More than 4,800 | Combinations that no longer bundle; modifiers previously needed are no longer required |
| Revised PTP pairs | Six | Usually a modifier indicator change from 0 to 1 or the reverse |
| New MUEs | 121 | Unit limits on codes that previously had none, many of them new 2026 codes |
| Revised MUE values | Seven | Includes G0447 reduced from two units to one per date of service |
| Add-on code edits | Updated file posted | Check any add-on codes your practice bills against the new primary code list |
The heavy concentration in Category III codes matters to practices doing newer procedures: emerging technologies carry temporary T codes, and as they mature CMS builds edits around them. Practices in interventional pain, cardiology, ophthalmology and gastroenterology tend to bill more of these than primary care does. The medicine-section changes reach further, because that section includes injections, infusions, diagnostic tests and many of the services that are billed alongside an office visit.
The G0447 change is the one we expect the most calls about. Behavioral counseling for obesity is a 15-minute code, and some practices have billed two units for a 30-minute session. From April 1 the MUE allows one unit per day for Medicare; the second unit will deny with CO-151 (payment adjusted because the payer deems the information submitted does not support this many services). Whether a longer session is worth documenting differently is a clinical and coding conversation, but billing two units is no longer an option.
How to read the files
The PTP file for practitioners is a spreadsheet with a row per pair. The columns you need are column 1 code, column 2 code, effective date, deletion date and modifier indicator. Filter to rows where the effective date is April 1, 2026 to see new edits; filter to rows where the deletion date is March 31, 2026 to see deleted ones. Then filter both lists to codes your practice bills.
The MUE file lists each code with its unit limit and an MUE adjudication indicator. Indicator 1 is a line-level edit; indicator 2 is a date-of-service edit that CMS considers an absolute limit; indicator 3 is a date-of-service edit that can be appealed with documentation. G0447 sits in the date-of-service category, so splitting units across two claim lines does not help. Reading the adjudication indicator tells you whether an appeal is even possible before you spend time on one.
Most practices do not open these files, and honestly most do not need to. Your clearinghouse and practice management vendor load them. What you do need is to know when they loaded them and to check your own high-volume combinations, which the next section covers.
Reconciling the update against your billing
Our method takes about two hours a quarter. Run a report of the code pairs your practice billed together on the same date of service in the last 90 days, ranked by frequency, and take the top 50. Look each pair up in the current PTP file. For each, note whether there is an edit, the modifier indicator, and whether either changed this quarter. The output is a short list: pairs that now need a modifier they did not need before, pairs that no longer need one, and pairs that now bundle absolutely.
Then do the same for units. Take your top 30 codes billed with more than one unit and check each against the MUE file. The G0447 change would surface here for any practice doing obesity counseling.
Push the results into three places: the scrubber rules, so claims are held before submission when a new edit applies; the charge entry cheat sheet, so coders know which combinations changed; and a short note to the physicians whose combinations are affected, in plain language, with the clinical scenario rather than the code numbers. Practices that use a billing partner should expect this reconciliation each quarter as part of the service and ask for the list.
The commercial payer lag
Medicare contractors apply the new edits on the effective date. Commercial payers and Medicare Advantage plans license NCCI or build their own versions of it, and they update on their own schedules, sometimes a quarter or more behind. For several weeks after April 1 you can have a claim that passes Medicare's edits and fails a commercial payer still running version 32.0, or the reverse.
The practical response is to keep both versions in mind when you work denials in April and May. A CO-236 or CO-97 from a commercial payer on a pair that Medicare no longer bundles is not a coding error; it is a version mismatch, and the appeal is a one-paragraph letter citing the current NCCI version and effective date. Some payers will pay; some will tell you their policy is to update in July. Document the answer and move on.
The reverse case is the one to watch. If a commercial payer adopts a new edit before your scrubber does, claims will deny that you expected to pay. When a new denial pattern appears in April, check the NCCI update before you assume the payer changed its policy.
Questions we hear
Can we appeal a PTP denial with modifier indicator 0?
Not on the basis of separate procedures; indicator 0 means the pair cannot be unbundled under any circumstances. The only successful arguments are that one of the codes was billed in error or that the dates of service were actually different. If the two services were genuinely distinct and both necessary, that is a comment to CMS about the edit, not an appeal of the claim.
Our scrubber flagged a pair as bundled but the physician says the services were separate. Who is right?
Possibly both. If the modifier indicator is 1 and the documentation shows the services were performed at separate sites, separate sessions or for separate lesions, the appropriate X modifier or modifier 59 on the column 2 code will pass the edit. The coder should read the note and apply the modifier only when the note actually supports the distinction.
Does NCCI apply to Medicaid?
Yes, but through a separate Medicaid NCCI program with its own files and a few differences from the Medicare version. State Medicaid agencies are required to use it. If your state Medicaid program or its managed care plans deny a pair that Medicare pays, check the Medicaid NCCI files before appealing.
What to do this week
- Confirm with your clearinghouse and practice management vendor that NCCI version 32.1 is loaded and the load date.
- Run the same-day code pair report for the last 90 days and check your top 50 pairs against the current PTP file.
- Check your top 30 multi-unit codes against the MUE file, including G0447 if you bill it.
- Update scrubber rules and the charge entry reference for any pair or unit limit that changed.
- Watch April denials for CO-236, CO-97 and CO-151 from commercial payers and separate version mismatches from real coding errors.
