CPT code 50430: Antegrade nephrostogram, existing access2026 Medicare rate & RVUs in Illinois
Reports contrast imaging of the renal collecting system and ureter through an established percutaneous access to assess drainage, patency, or obstruction.
Medicare pays $578.85–$640.14 for 50430 in the office in Illinois, from Rest of Illinois to Suburban Chicago, IL. Which amount applies depends on the service address.
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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On this page 9 sections
What 50430 covers
A radiologist, interventional radiologist, or urologist injects contrast through an existing nephrostomy or other percutaneous urinary access and images the renal collecting system and ureter. The study can clarify whether contrast passes into the bladder, identify an obstruction or leak, or assess the position and function of an existing drainage catheter. It is performed in a setting equipped for image-guided urinary procedures.
Report 50430 when the diagnostic antegrade study uses established access; 50431 is the corresponding code when access is newly obtained. The service includes imaging guidance and the associated radiological supervision and interpretation, so those elements are not separately reported for the same study. Documentation should identify the access used, the contrast study performed, and the diagnostic findings. The code has a 0-day global period, including same-day preoperative and postoperative care. When multiple procedures occur in one session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. Modifier 50 applies to a bilateral procedure, paid at 150%. Assistant-at-surgery payment requires documented medical necessity; co-surgeons and team surgery are 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 50430 pays more and less in Illinois
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
4 payment localities
$578.85 to $640.14
| Payment locality | Office | Facility |
|---|---|---|
| Chicago, IL | $634.84 | $151.12 |
| East St. Louis, IL | $587.55 | $144.74 |
| Rest of Illinois | $578.85 | $139.42 |
| Suburban Chicago, IL | $640.14 | $145.84 |
How the 50430 rate is calculated
Each of 50430’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 · 50430
RVUs × geographic indexes × conversion factor
Work2.83
2.83 RVUs× 1.000 GPCI
Practice expense15.30
15.30 RVUs× 1.000 GPCI
Malpractice0.34
0.34 RVUs× 1.000 GPCI
Adjusted RVUs
18.4700
Conversion factor
$33.4009
Medicare rate
$616.91
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 50430
The CMS indicators that decide how 50430 is paid alongside other services.
CMS payment indicators · 50430
Antegrade nephrostogram, existing access
| 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) | 1 | Bilateral with modifier 50 pays 150% of the fee schedule amount. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
What modifiers do to the payment
Modifier 50 · payment effect
With and without the modifier
50430 without 50 · national office
$616.91
Antegrade nephrostogram, existing access
50430-50 · Bilateral: 150%
$925.37
Both sides on one line with modifier 50 are paid at 150% of the fee schedule amount (subject to multiple-procedure rules with other procedures).
50430 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 50431Antegrade contrast studyNew access
- The access circumstance distinguishes the codes: 50430 uses established access, while 50431 applies when access is newly obtained for the study.
- 50432Nephrostomy placementNew percutaneous access
- 50430 is a contrast study through established access; 50432 reports placement of a nephrostomy catheter to establish drainage.
- 50435Nephrostomy exchangeExisting percutaneous access
- 50430 reports diagnostic contrast imaging through existing access. Use 50435 when the performed service is exchange of a nephrostomy catheter.
50430 billing questions
When should 50430 be chosen over 50431?
Use 50430 for the antegrade study through established percutaneous access. Use 50431 when access is newly obtained for the study.
Can imaging guidance or radiological interpretation be billed separately?
No. The code includes imaging guidance and associated radiological supervision and interpretation for the study.
How should bilateral studies be reported?
For a bilateral procedure, report modifier 50; CMS pays the procedure at 150%.
How does payment work when another procedure is performed in the same session?
The highest-valued procedure is paid in full, and other procedures are subject to the standard multiple procedure reduction, with payment at 50%.
What documentation supports 50430?
Document that the access was established before the study, the contrast imaging performed, and the findings relevant to drainage, patency, obstruction, leak, or catheter position.
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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