A 33361 with modifier 62 denying for a missing or inconsistent modifier usually means Medicare also expected modifier Q0. For TAVR dates of service before September 10, 2026, bill 33361-62-Q0 with Z00.6, the aortic stenosis code, and the 8-digit trial number.
The rules changed on September 10, 2026. CMS updated NCD 20.32 that day. This guide shows the old and new rules, where to find the NCT number, and how to fix the claim.
TL;DR: The remark “modifier inconsistent or missing” is CARC 4. Before September 10, 2026, Medicare returned TAVR lines without Q0 as unprocessable. After that date, symptomatic severe aortic stenosis no longer needs the registry items. Asymptomatic cases in a CMS-approved study still do.
Written by Manikandan J, CPC, CRCR, a certified coder and revenue cycle specialist. Published 10 November 2026. Last updated: 10 November 2026.
Table of Contents
Why is 33361 with modifier 62 denying?
33361 with modifier 62 is denying because Medicare’s TAVR edit checks more than one item. For older dates of service, the line also needed modifier Q0, diagnosis Z00.6, and a trial number. A missing Q0 returns as CARC 4, “modifier inconsistent or missing.”
CPT 33361 is transcatheter aortic valve replacement (TAVR/TAVI) with a prosthetic valve by a percutaneous femoral artery approach. It is the most common TAVR code. Codes 33362 to 33366 cover the other entry routes.
Modifier Q0 is the HCPCS modifier for an investigational clinical service provided in an approved clinical research study. TAVR used it because Medicare paid for TAVR only with a national registry. That rule is called Coverage with Evidence Development.
Our CO-4 denial code guide explains CARC 4 in general. Medicare Advantage plans may use their own edits, but many follow the NCD.
What did Medicare require on TAVR claims before September 10, 2026?
Before September 10, 2026, Medicare required five items on every professional TAVR claim. They were POS 21, modifier 62, modifier Q0, diagnosis Z00.6, and the 8-digit ClinicalTrials.gov number. The Claims Processing Manual, Chapter 32, Section 290.2, sets each rule.
| Claim item | Requirement | Denial if missing |
|---|---|---|
| Place of service | POS 21, inpatient hospital | CARC 58, invalid place of service |
| Modifier 62 | Two surgeons as co-surgeons | CARC 4, returned as unprocessable |
| Modifier Q0 | Approved clinical study service | CARC 4, returned as unprocessable |
| Diagnosis Z00.6 | Clinical research encounter, listed with I35.0 | CARC 16 with RARC M76 |
| Trial number | 8 digits, such as 01737528 | CARC 16 with RARC MA50 |
So 33361-62 alone was never enough for those dates. A clean line read 33361-62-Q0, with I35.0 (nonrheumatic aortic stenosis) and Z00.6 as diagnoses. For example, both the cardiac surgeon and the interventional cardiologist billed that same line.
In my AR work, I have seen surgeons’ claims pay while the cardiologist’s claim bounced. The second claim almost always lacked Q0 or the trial number.
What changed for TAVR claims after September 10, 2026?
After September 10, 2026, TAVR for symptomatic severe aortic stenosis is covered without the registry rule. So Z00.6 and the trial number are not required for those cases. Modifier 62 is needed only when the heart team chooses joint participation by two surgeons.
CMS posted the final decision memo for NCD 20.32 on September 10, 2026. It also added coverage for severe aortic stenosis with no symptoms, but only inside an approved study. A change request to update the manuals is still to come.
Until that change request lands, MACs have posted interim rules. CGS, for example, lists these for dates of service on or after September 10, 2026:
- Bill type 11X or POS 21 only.
- Modifier 62 only when joint participation is appropriate.
- Z00.6 and the 8-digit trial number only for asymptomatic cases in a CMS-approved study.
- Claims sent with registry details still process under the clinical trial rules.
The date of service decides which rules apply. Check your own MAC’s notice too. Edits can lag behind the policy.
How do you find the NCT number for a TAVR claim?
You find the NCT number on the CMS TAVR coverage page or on ClinicalTrials.gov. For most TAVR cases before September 10, 2026, it was the STS/ACC TVT Registry, NCT01737528. Enter only the 8 digits, 01737528, on the electronic claim.
Where it goes depends on the claim form. On the 837P, enter the number in Loop 2300, REF02, with REF01 set to P4. On a paper CMS-1500, enter “CT01737528” in Item 19. Studies approved after that date have their own numbers on the CMS TAVR page.
Ask your heart program office which registry or study the hospital uses. The number must match the study the patient is in.
How do you fix a denied 33361 claim?
Fix a denied 33361 claim by sending a new, corrected claim with the missing items. Medicare returns these lines as unprocessable. So there is no appeal right. Check the date of service first, then add Q0, Z00.6, and the trial number when the old rules apply.
- Read the remit. CARC 4 points to a modifier. CARC 16 with M76 or MA50 points to the diagnosis or trial number.
- Check the date of service against September 10, 2026.
- For older dates, rebill 33361-62-Q0 with I35.0, Z00.6, and NCT 01737528.
- For newer symptomatic cases, drop items that no longer apply. Keep 62 only for joint participation.
- Confirm POS 21 on the professional claim.
Our corrected claim guide covers resubmission by payer. See the CO-16 denial code guide and the CO-58 place of service guide for related remits. The timely filing calculator checks your deadline.
3-step checklist
- Match the date of service to the old or new NCD 20.32 rules.
- Add Q0, Z00.6, and the 8-digit NCT number when the old rules apply.
- Send a new claim with POS 21 and modifier 62 only when two surgeons operated.
FAQ
What modifiers go on 33361 for Medicare?
For dates of service before September 10, 2026, Medicare required 33361-62-Q0. After that date, symptomatic cases do not need Q0, and modifier 62 applies only when two surgeons jointly perform the procedure.
What does CARC 4 mean on a TAVR claim?
CARC 4 means the procedure code is inconsistent with the modifier or a required modifier is missing. On older TAVR claims, it usually means modifier 62 or Q0 was missing.
What is the NCT number for the TVT Registry?
The STS/ACC TVT Registry number is NCT01737528. Enter 01737528 in the 837P Loop 2300 REF02 with qualifier P4, or CT01737528 in Item 19 on a paper claim.
Is Z00.6 still required for TAVR?
For dates of service on or after September 10, 2026, Z00.6 is required only when asymptomatic severe aortic stenosis is treated in a CMS-approved study, per MAC interim instructions.
Can you appeal a TAVR claim returned as unprocessable?
No. An unprocessable claim has no appeal rights. Fix the missing items and send a new claim within the timely filing limit.
Sources
My methodology was simple. I read the CMS manual section line by line, then checked the 2026 NCD update and a MAC notice. Rules are changing now, so confirm your MAC’s current instructions before you bill.
- CMS, Medicare Claims Processing Manual, Pub. 100-04, Chapter 32, Section 290 (TAVR). Accessed 10 Nov 2026.
- CMS, TAVR Decision Memo, CAG-00430R2 (NCD 20.32). Accessed 10 Nov 2026.
- CMS, Coverage with Evidence Development: Transcatheter Aortic Valve Replacement. Accessed 10 Nov 2026.
- CGS Medicare, Revised: NCD 20.32 – Transcatheter Aortic Valve Replacement (November 3, 2026). Accessed 10 Nov 2026.
- CMS, Mandatory Clinical Trial Identifier Number on claims. Accessed 10 Nov 2026.
- ClinicalTrials.gov, STS/ACC TVT Registry, NCT01737528. Accessed 10 Nov 2026.
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Last updated: 10 November 2026 · Educational content for U.S. billers. Payer policies vary by plan, so check the plan’s current policy.
