FeeBase
Log inGet started
Menu

Billing code 33420: Mitral valvotomyMedicare rate & RVUs

Reports closed surgical opening of fused mitral valve commissures to relieve stenosis, typically in patients with rheumatic mitral valve disease.

CMS RVU26DEffective Oct 1, 2026109 payment localities

Medicare pays $1,387.14 for 33420 nationally in a facility.

Medicare rate · 33420

Mitral valvotomy

Swap in your local Medicare rate.

Work RVUs
25.15
Total RVUs
41.53
Global days
090

National rate · 2026

$1,387.14

Facility setting, before claim adjustments.

See every locality for 33420 → · Billed by an NP, PA or therapist? →

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

On this page 10 sections
  1. Medicare rate
  2. What 33420 covers
  3. By payment locality
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Similar codes
  8. Related codes
  9. Billing questions
  10. Sources

What 33420 covers

This code describes a closed surgical mitral valvotomy, also called a commissurotomy, in which fused areas of the mitral valve are separated to improve blood flow through a narrowed valve. Cardiothoracic surgeons have traditionally performed it for mitral stenosis, often related to rheumatic disease. The surgeon works without opening the heart to directly visualize the valve; this distinguishes the procedure from an open-heart valvotomy and from catheter-based valve treatment.

Report the code when the operative report supports a closed valvotomy to relieve mitral stenosis, not a valve repair or replacement. Documentation should identify the stenotic valve and describe the surgical approach and commissural separation. CMS assigns a 90-day global period, including the day-before preoperative visit and related postoperative care during that period. When multiple procedures occur in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. Assistant-at-surgery payment is restricted by statute; co-surgeon payment requires supporting documentation, and team surgery is not permitted.

This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.

Where 33420 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

33420 office and facility rates by payment locality
Payment localityOfficeFacility
AlabamaUnavailable$1,256.62
Alaska*Unavailable$1,739.37
ArizonaUnavailable$1,347.46
ArkansasUnavailable$1,240.83
AtlantaUnavailable$1,435.61
AustinUnavailable$1,385.97
BakersfieldUnavailable$1,357.70
Baltimore/Surr. CntysUnavailable$1,473.49
BeaumontUnavailable$1,341.72
BrazoriaUnavailable$1,346.51

33420 rates by state

Office rate range in each state. Select a state to see its payment localities.

MEWIVTNHMTNDMNMINYMARIWAIDWYSDIAILINOHPANJCTORNVUTCONEMOKYWVVAMDDECAAZNMKSOKARTNNCSCDCTXLAMSALGAFLAKHI

Explore a state

Local rates. Clear comparisons.

Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.

View every state and territory as a table
33420 office rate range by state
State / territoryOffice rate rangeLocalities
AKNo published base rate1
ALNo published base rate1
ARNo published base rate1
AZNo published base rate1
CANo published base rate29
CONo published base rate1
CTNo published base rate1
DCNo published base rate1
DENo published base rate1
FLNo published base rate3
GANo published base rate2
GUNo published base rate1
HINo published base rate1
IANo published base rate1
IDNo published base rate1
ILNo published base rate4
INNo published base rate1
KSNo published base rate1
KYNo published base rate1
LANo published base rate2
MANo published base rate2
MDNo published base rate3
MENo published base rate2
MINo published base rate2
MNNo published base rate1
MONo published base rate3
MSNo published base rate1
MTNo published base rate1
NCNo published base rate1
NDNo published base rate1
NENo published base rate1
NHNo published base rate1
NJNo published base rate2
NMNo published base rate1
NVNo published base rate1
NYNo published base rate5
OHNo published base rate1
OKNo published base rate1
ORNo published base rate2
PANo published base rate2
PRNo published base rate1
RINo published base rate1
SCNo published base rate1
SDNo published base rate1
TNNo published base rate1
TXNo published base rate8
UTNo published base rate1
VANo published base rate2
VINo published base rate1
VTNo published base rate1
WANo published base rate2
WINo published base rate1
WVNo published base rate1
WYNo published base rate1

How the 33420 rate is calculated

Each of 33420’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.

How the rate is built · 33420

RVUs × geographic indexes × conversion factor

Swap in your local Medicare rate.

Work 25.15Practice expense 10.36Malpractice 6.02

41.5300 adjusted RVUs×$33.4009 conversion factor=$1,387.14

All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.

Payment rules and modifiers for 33420

33420 has a 90-day global period: related visits in that window are included in the surgery payment.

CMS payment indicators · 33420

Mitral valvotomy

RuleCMS valueWhat it means
Global period090Major surgery: the day before, the day of, and 90 days after are included.
Multiple procedures2Standard reduction: highest-valued procedure at 100%, others at 50%.
Bilateral (modifier 50)0The 150% bilateral adjustment doesn’t apply.
Assistant at surgery (80/81/82/AS)1Not paid (statutory restriction).
Co-surgeons (62)1Permitted with supporting documentation.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.
Split (54/55/56)0.09/0.84/0.07Share of the payment for pre-op, the procedure itself, and post-op care.

Global surgery period · 33420

Mitral valvotomy

90-day global period ends

Dec 30, 2026

Covers Sep 30, 2026 through Dec 30, 2026 (92 days, including the day before surgery).

Visit on Oct 31, 2026

Day 30 of the 90-day post-op period: related follow-up care is included in the surgical payment.

  • 24 Unrelated E/M visit by the same physician
  • 79 Unrelated procedure (starts its own global period)
  • 58 Staged, more extensive, or therapy procedure that was planned
  • 78 Unplanned return to the operating room for a related complication
SurgeryVisit
Sep 23, 2026Jan 10, 2027

Pre-op dayGlobal period

What modifiers do to the payment

Modifier 51 · payment effect

With and without the modifier

33420 without 51 · national facility

$1,387.14

Mitral valvotomy

33420-51 · Second procedure: 50%

$693.57

When this isn’t the highest-valued procedure in the session, Medicare pays 50% of its fee schedule amount (the highest is paid at 100%).

When to use modifier 51

33420 compared with similar codes

Compare codes

33420 vs 33422 vs 33425 vs 33430: national Medicare rates

Swap in your local Medicare rate.

  • 33420
    Mitral valvotomy · 25.15 wRVU
    —
  • 33422
    Mitral valvotomy · 28.99 wRVU
    —
  • 33425
    Mitral valve repair · 48.71 wRVU
    —
  • 33430
    Mitral valve replacement · 49.66 wRVU
    —

How to choose

33422Mitral valvotomy
Choose 33420 for closed surgical commissurotomy. Choose 33422 when the mitral valve is treated by open-heart valvotomy with cardiopulmonary bypass.
33425Mitral valve repair
Code 33425 describes mitral valve repair, not commissural separation for stenosis. Select based on the operation documented.
33430Mitral valve replacement
Code 33430 is for mitral valve replacement. It is not the code for a closed procedure that opens fused commissures while retaining the native valve.

Codes related to 33420

Related codes aren’t interchangeable: bill the code that matches the service performed.

Codes related to 33420
CodeHow it relatesNational office range
Same family
33422Mitral valvotomyOpen-heart mitral valvotomy; differs from this code's closed surgical approach.No office rate
Used instead
33425Mitral valve repairMitral valve repair is reported when the operation reconstructs the valve rather than performing valvotomy.No office rate
33430Mitral valve replacementMitral valve replacement is reported when the operation replaces rather than opens the native valve.No office rate

33420 billing questions

How is this different from 33422?

Both codes describe mitral valvotomy, but 33420 is for the closed surgical approach. Code 33422 is for an open-heart valvotomy performed with cardiopulmonary bypass.

When should a mitral repair code be used instead?

Use a repair code when the operation reconstructs the mitral valve rather than separating fused commissures to relieve stenosis. The operative report should establish the procedure actually performed.

Is postoperative care included?

Yes. The 90-day global period includes the day-before preoperative visit and related postoperative care during the 90 days after surgery.

Can this be reported with another procedure performed in the same session?

When multiple procedures are performed in the same session, CMS pays the highest-valued procedure in full and applies the standard 50% reduction to the others.

What documentation supports co-surgeon billing?

Co-surgeon payment requires supporting documentation. The operative record should substantiate the surgeons’ roles in this mitral valve procedure.

Can an assistant surgeon be paid for this procedure?

CMS statutory restrictions bar assistant-at-surgery payment for this code. Team-surgery payment is not permitted.

Where these rates come from

FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.

CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027

Show the CMS file lines behind this rate
RVUs for 33420PPRRVU2026_Oct_nonQPP.csv, line 3,950 (RVU26D)

Open CMS sourceHow we calculate rates

Did this answer your question about what 33420 pays?

Tell us what you were actually trying to work out. We’ll answer you directly, or build the page that does.

Fee sheets

Put 33420 and the rest of your codes on one sheet

Build a fee sheet from your own code list at your locality, put your payer contracts beside Medicare, and see what changed each quarter.

Build my fee sheetOr price your code list free →