CPT code 33988: Left heart vent, insertion2026 Medicare rate & RVUs in Michigan
Reports surgical placement of a left heart vent to decompress the left-sided chambers during cardiac surgery, typically while the patient is on cardiopulmonary bypass.
CMS doesn’t publish an office rate for 33988 in Michigan.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
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What 33988 covers
A left heart vent temporarily drains blood from the left side of the heart to help prevent chamber distention during cardiac surgery. A cardiothoracic surgeon typically places it in the operating room as part of an open cardiac procedure, often while the patient is supported by cardiopulmonary bypass. The operative report should identify the placement and the vent’s role in the procedure.
Report 33988 for the insertion service, not for removal of the vent; distinguish the work from the principal cardiac operation in the documentation. CMS assigns a 0-day global period, so same-day preoperative and postoperative care is included. When multiple procedures are performed in the same session, the highest-valued procedure is paid in full and the others at 50%. Modifier 50 is inappropriate for this code. Assistant-at-surgery, co-surgeon, and team-surgery payment each require supporting documentation; assistant payment specifically requires medical necessity.
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 33988 pays more and less in Michigan
| Payment locality | Office | Facility |
|---|---|---|
| Detroit, MI | Unavailable | $787.04 |
| Rest of Michigan | Unavailable | $716.63 |
How the 33988 rate is calculated
Each of 33988’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 · 33988
RVUs × geographic indexes × conversion factor
Work14.63
14.63 RVUs× 1.000 GPCI
Practice expense3.16
3.16 RVUs× 1.000 GPCI
Malpractice3.49
3.49 RVUs× 1.000 GPCI
Adjusted RVUs
21.2800
Conversion factor
$33.4009
Medicare rate
$710.77
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 33988
The CMS indicators that decide how 33988 is paid alongside other services.
CMS payment indicators · 33988
Left heart vent, insertion
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 000 | Same-day global: pre- and post-op care on the day of the procedure is included. |
| Multiple procedures | 2 | Standard reduction: highest-valued procedure at 100%, others at 50%. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 1 | Permitted with supporting documentation. |
| Team surgery (66) | 1 | Permitted with supporting documentation. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
What modifiers do to the payment
Modifier 51 · payment effect
With and without the modifier
33988 without 51 · national facility
$710.77
Left heart vent, insertion
33988-51 · Second procedure: 50%
$355.39
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%).
33988 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 33989Heart vent removalLeft heart vent
- 33988 is for placing the left heart vent; 33989 is for removing it.
- 33990VAD insertionLeft heart, arterial access
- 33990 covers percutaneous insertion of a left heart ventricular assist device, not surgical placement of a vent for decompression.
- 33991VAD insertionLeft heart, arterial and venous access
- 33991 describes percutaneous left heart VAD insertion using arterial and venous access; 33988 reports left heart vent insertion.
33988 billing questions
How does insertion differ from removal of a left heart vent?
Use 33988 for placement. Code 33989 describes the removal service.
What documentation supports reporting 33988?
The operative report should establish that the surgeon placed a left heart vent and describe its role in the cardiac procedure.
Is modifier 50 appropriate?
No. CMS identifies bilateral adjustment as inappropriate for this code.
How does the multiple-procedure rule affect payment?
For procedures performed in the same session, CMS pays the highest-valued procedure in full and the other procedures at 50%.
Can an assistant surgeon or co-surgeon be reported?
Assistant-at-surgery payment requires documentation of medical necessity. Co-surgeon and team-surgery payment require supporting documentation.
Does the code include same-day postoperative care?
Yes. The 0-day global period includes same-day preoperative and postoperative care.
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
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