Billing code 35646: Aortic bypassMedicare rate & RVUs in Washington
Reports a non-vein bypass from the aorta to both femoral arteries, commonly performed to restore lower-extremity blood flow in aortoiliac occlusive disease.
CMS doesn’t publish an office rate for 35646 in Washington.
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 35646 covers
A vascular surgeon uses a conduit other than vein, typically a synthetic graft, to route blood from the aorta to the femoral artery in each groin. This operation is commonly performed in an operating room for extensive aortoiliac occlusive disease causing significant lower-extremity ischemia. The graft’s two limbs provide anatomic outflow to both sides; the operative report should identify the aortic inflow, both femoral targets, and conduit material.
Report this code when the bypass runs from the aorta to both femoral arteries using a non-vein conduit. Documentation should establish the indication, graft route and material, and the two distal anastomoses. CMS assigns a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. When multiple procedures are performed in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. An assistant at surgery may be paid; 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 35646 pays more and less in Washington
| Payment locality | Office | Facility |
|---|---|---|
| Rest Of Washington | Unavailable | $1,502.26 |
| Seattle (King Cnty) | Unavailable | $1,591.40 |
How the 35646 rate is calculated
Each of 35646’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 · 35646
RVUs × geographic indexes × conversion factor
Work32.16
32.16 RVUs× 1.000 GPCI
Practice expense5.87
5.87 RVUs× 1.000 GPCI
Malpractice8.17
8.17 RVUs× 1.000 GPCI
Adjusted RVUs
46.2000
Conversion factor
$33.4009
Medicare rate
$1,543.12
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 35646
35646 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 35646
Aortic bypass
| 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 · 35646
Aortic bypass
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
35646 without 51 · national facility
$1,543.12
Aortic bypass
35646-51 · Second procedure: 50%
$771.56
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%).
35646 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 35647Aortic bypass
- Use 35646 when the aortic bypass reaches both femoral arteries. Use 35647 when it reaches one femoral artery.
- 35521Arterial bypass
- Both describe an aortic-to-femoral bypass, but 35521 is the vein-conduit alternative; 35646 uses a conduit other than vein and reaches both femoral arteries.
- 35638Aortic bypass
- 35638 routes the aortic bypass to both iliac arteries. 35646 routes it to both femoral arteries.
- 35654Arterial bypass
- 35654 uses axillary inflow with a femoral-femoral configuration. 35646 uses aortic inflow and reaches both femoral arteries.
35646 billing questions
How does 35646 differ from 35647?
35646 describes an aortic bypass to both femoral arteries. 35647 is the related aortofemoral code for a bypass to one femoral artery.
Does the conduit material affect code selection?
Yes. 35646 is for a conduit other than vein, typically a synthetic graft. For an aortofemoral bypass using vein, compare 35521.
Is a separate bypass code reported for each graft limb?
No. The two femoral destinations are part of the aortobifemoral bypass represented by 35646; document both distal targets in the operative report.
What documentation supports reporting 35646?
The operative report should show aortic inflow, bypass to both femoral arteries, the graft route, and use of a non-vein conduit.
How does the multiple-procedure payment rule affect another same-session procedure?
When another procedure is performed in the same session, CMS pays the highest-valued procedure in full and applies the standard 50% reduction to the others.
What are the assistant and co-surgeon payment rules?
An assistant at surgery may be paid. Co-surgeon payment requires supporting documentation; CMS does not permit team surgery.
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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