CPT code 36831: Fistula thrombectomy2026 Medicare rate & RVUs in Texas
Open removal of thrombus from a hemodialysis arteriovenous fistula without revising the access when clot obstructs fistula flow.
CMS doesn’t publish an office rate for 36831 in Texas.
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 9 sections
What 36831 covers
This service removes obstructing clot from a surgically created arteriovenous fistula through open surgical exposure, with the goal of restoring access flow. Vascular surgeons and other surgeons who manage dialysis access typically perform it in an operating room when a fistula has thrombosed. The code describes thrombectomy without revision of the fistula; it is not for declotting a cannula or treating a graft as though it were a fistula.
Report the code when the operative record supports open clot removal from the fistula and no access revision is performed. Document the access site, open approach, thrombus removal, and whether the fistula was revised; when thrombectomy accompanies revision, consider 36833 instead. CMS assigns a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. For multiple procedures in one session, the highest-valued procedure is paid in full and others at 50%. Modifier 50 is inappropriate. Assistant-at-surgery payment may be available; 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 36831 pays more and less in Texas
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
8 of 8 payment localities
| Payment locality | Office | Facility |
|---|---|---|
| Austin | Unavailable | $562.76 |
| Beaumont | Unavailable | $548.89 |
| Brazoria | Unavailable | $547.43 |
| Dallas | Unavailable | $555.53 |
| Fort Worth | Unavailable | $555.57 |
| Galveston | Unavailable | $552.07 |
| Houston | Unavailable | $602.41 |
| Rest Of Texas | Unavailable | $551.01 |
How the 36831 rate is calculated
Each of 36831’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 · 36831
RVUs × geographic indexes × conversion factor
Work10.73
10.73 RVUs× 1.000 GPCI
Practice expense3.46
3.46 RVUs× 1.000 GPCI
Malpractice2.75
2.75 RVUs× 1.000 GPCI
Adjusted RVUs
16.9400
Conversion factor
$33.4009
Medicare rate
$565.81
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 36831
36831 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 36831
Fistula thrombectomy
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 090 | Major surgery: the day before, the day of, and 90 days after are 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) | 2 | Paid. |
| Co-surgeons (62) | 1 | Permitted with supporting documentation. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
| Split (54/55/56) | 0.09/0.84/0.07 | Share of the payment for pre-op, the procedure itself, and post-op care. |
Global surgery period · 36831
Fistula thrombectomy
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.
Pre-op dayGlobal period
What modifiers do to the payment
Modifier 51 · payment effect
With and without the modifier
36831 without 51 · national facility
$565.81
Fistula thrombectomy
36831-51 · Second procedure: 50%
$282.91
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%).
36831 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 36832Fistula revision
- 36832 describes open fistula revision without thrombectomy. Choose 36831 when open clot removal is performed without revising the access.
- 36833Fistula revision
- 36833 applies when open fistula revision and thrombectomy are both performed. 36831 is for thrombectomy without revision.
- 36860Cannula declotting
- 36860 concerns declotting an external dialysis cannula. 36831 is for open removal of thrombus from the fistula itself.
- 36861Cannula declotting
- 36861 is a cannula-declotting service, while 36831 addresses open thrombectomy of the arteriovenous fistula.
36831 billing questions
When should 36831 be chosen over 36833?
Use 36831 for open fistula thrombectomy without revision. When the surgeon revises the fistula and removes thrombus during the procedure, 36833 describes that combination.
Can 36831 be reported for declotting a dialysis cannula?
No. This code concerns open thrombectomy of the arteriovenous fistula itself; codes 36860 and 36861 concern cannula declotting.
What documentation supports reporting 36831?
The operative report should identify the fistula, describe open exposure and removal of thrombus, and clarify whether revision was performed.
Does modifier 50 apply when fistulas are treated on both sides?
CMS identifies bilateral adjustment as inappropriate for this code. Do not use modifier 50.
How does the 90-day global period affect postoperative reporting?
The day-before preoperative visit and 90 days of related postoperative care are included in the global period.
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
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