Do I need to be a coding expert to use this?

No. The helper asks about everyday situations, such as whether the patient came back later the same day, and explains each result in plain English. The only thing you need is one number from a free Medicare file, and the page shows where to find it.

Does this tool look up Medicare’s rules for me?

No. It does not contain Medicare’s code lists, because they change every quarter and CMS publishes them. It applies CMS’s published rules to the number you read from the official file and to what the medical record shows.

Is this the same as the CCI edit checker my billing software has?

CCI is the older name for the same program, the National Correct Coding Initiative. Your software checks code pairs against the files. This helper explains what to do once you have the indicator, and which modifier, if any, the facts support.

Can I use it for commercial payers?

NCCI is CMS’s program for Medicare, and states apply compatible methods in Medicaid. Many commercial payers use similar edits, but each sets its own policy, so confirm with the payer.

Is my information stored?

No. Everything runs in your browser. Nothing you enter is sent, stored or logged. Do not type patient names or other identifiers.

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NCCI edit helper

Free tool

Why did Medicare deny this, and can it be fixed?

Medicare refused to pay for a service, or for too many units? Answer a few simple questions and get a plain-English answer and your next steps. No expert knowledge needed, about two minutes, and no patient information.

Example

Main service

Paid

Second service

Denied

Can a modifier fix it?

Never

Sometimes

No rule

Then: we show the most specific modifier that fits, and what the medical record must prove.

What is this, in plain English?

Medicare checks every claim against a set of rules called NCCI edits. Two of them cause most surprises:

Services that should not be billed together. Medicare pays one and denies the other, unless a small add-on code (a “modifier”) is allowed and the facts back it up.
Too many units. Medicare has a daily limit for how many times it expects one service to be billed.

Words you will see, explained

Modifier: A two-character add-on to a billing code that gives Medicare extra information, such as “this was the left side” or “this was a separate visit.”
Column One / Column Two: When two codes are paired by a rule, Column One is the main one that gets paid. Column Two is the one that gets denied unless a modifier is allowed and fits.
Modifier indicator: A 0, 1 or 9 on the Medicare rule that says whether a modifier may be used. 0 means never, 1 means sometimes, 9 means the rule is not in effect.
MUE (medically unlikely edit): The most units of one service Medicare expects to be billed for one patient, from one provider, on one day.
MAI: A 1, 2 or 3 next to an MUE that says how strict the limit is and whether you can appeal it.
Unit: How many times a service is counted on the claim, such as two injections billed as 2 units.
Global period: The days after surgery when follow-up care is already covered by the surgery payment.
ABN: A form that lets a provider bill a patient when Medicare may not pay. It cannot be used for units denied by an MUE.

What happened to your claim?

Two services were denied togetherMedicare paid one service and refused the other, or said the two belong together.Too many units were deniedMedicare says you billed more of one service than it normally allows in a day.

Two services were denied together

Step 1. What does the Medicare rule for this pair say about modifiers?

You look this up in a free CMS file. It is a single number, 0, 1 or 9, on the row for your two codes. Where do I find it?

1A modifier is allowedIt may be fixable0A modifier is never allowedIt cannot be fixed with a modifier9The rule is not in effectNothing is blocking you?I have not looked it up yetWe will show you where

Step 2. Which of these matches what the medical record says?

The patient came back for a second, separate visit the same dayFor example, seen in the morning and again in the afternoon.The two services were on different body partsLeft and right sides, different organs, or different areas. “They are different procedures” is not enough on its own.Two different providers each did one of the servicesEach provider did their own service for the patient.One service is clearly separate from the main oneNot a separate visit, body part or provider, but also not a normal part of the main service.Two timed services done in separate blocks of timeFor example, therapy billed in 15-minute units.An office visit on the same day as a small procedureA real, separate visit, not just the decision to do the procedure. (Applies to minor procedures and most “XXX” procedures.)The visit where the doctor decided on a major surgeryOn the day of, or the day before, a major (90-day) surgery.A visit for an unrelated problem soon after surgeryDuring the “global period” (the weeks after surgery that the surgery payment already covers).A planned, staged or bigger procedure soon after surgeryIncluding treatment that follows a diagnostic procedure.A procedure for a different problem soon after surgeryA procedure that has nothing to do with the original surgery.Back to the operating room for a problem from the surgeryAn unplanned return for something related to the first surgery.The same lab test had to be repeated that dayRepeated to get a new result.Same body part, same visit: just two different proceduresNo separate visit, body part, spot or time block. Only two procedure codes.

Tell us what happened

In plain English: Maybe. A “1” means a modifier is allowed, but only if the two services were really separate. Pick the situation that matches what is in the record.

Want the full explanation? Read NCCI edits explained.

Where do I find the number?

Medicare publishes its rules as free downloadable files. You only need one row from them. These four steps get you there.

Open the CMS Medicare NCCI page
CMS publishes the edit files on its Medicare NCCI pages: procedure-to-procedure (PTP) edits, medically unlikely edits (MUEs) and add-on code edits. Pick the practitioner, hospital outpatient or DME file that matches your claim.
Choose the file for your date of service
The files change every quarter, with effective dates around January 1, April 1, July 1 and October 1. Use the one in effect on the date of service, not today’s.
Find the pair or the code
In the Column One/Column Two file, search for your Column One code and then the Column Two code. Deleted edits stay in the file with a deletion date. In the MUE table, search for the single code.
Read the row, then come back to the helper
For two services, find the “modifier indicator”: a 0, 1 or 9. For units, find the daily limit (the MUE) and the 1, 2 or 3 beside it. Enter them in the helper above.

What one row in the Medicare file looks like (illustration, not real codes)

Column One
Code A
Eligible for payment
Column Two
Code B
Denied unless a modifier applies
Effective date
2015-01-01
When the edit began
Deletion date
blank or a date
Blank means still active
Modifier indicator
0 · 1 · 9
The one to enter below
Rationale
Reason for the edit
Why CMS bundles the pair

Common questions

Do I need to be a coding expert to use this?: No. The helper asks about everyday situations, such as whether the patient came back later the same day, and explains each result in plain English. The only thing you need is one number from a free Medicare file, and the page shows where to find it.
Does this tool look up Medicare’s rules for me?: No. It does not contain Medicare’s code lists, because they change every quarter and CMS publishes them. It applies CMS’s published rules to the number you read from the official file and to what the medical record shows.
Is this the same as the CCI edit checker my billing software has?: CCI is the older name for the same program, the National Correct Coding Initiative. Your software checks code pairs against the files. This helper explains what to do once you have the indicator, and which modifier, if any, the facts support.
Can I use it for commercial payers?: NCCI is CMS’s program for Medicare, and states apply compatible methods in Medicaid. Many commercial payers use similar edits, but each sets its own policy, so confirm with the payer.
Is my information stored?: No. Everything runs in your browser. Nothing you enter is sent, stored or logged. Do not type patient names or other identifiers.

Want the full explanation? Read NCCI edits explained.

General education based on CMS’s NCCI pages and the 2026 Medicare NCCI Policy Manual; not legal, coding or billing advice. Edits change quarterly, so confirm against the file in effect on your date of service and your contractor’s guidance. CPT® is a registered trademark of the American Medical Association; this tool uses modifier codes and code numbers only.