FeeBase
Log inGet started
Menu

CPT code 50391: Renal instillation, through nephrostomy access2026 Medicare rate & RVUs in King County, WA

Reports delivery of a therapeutic agent into the renal pelvis or ureter through nephrostomy access, with radiologic supervision and interpretation included.

CMS RVU26DEffective Oct 1, 2026One payment locality1.3K Medicare services in 2024

In King County, WA, Medicare pays $141.57 for 50391 in the office and $89.52 when it’s performed in a hospital or facility.

$141.57Office (non-facility)
$89.52Hospital or facility
+11.2%vs the national office rate ($127.26)

Check a contract rate as a % of Medicare · 50391 nationwide

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

We’ll open 50391 for the payment locality that covers the ZIP.

On this page 11 sections
  1. Rate in King County, WA
  2. What 50391 covers
  3. Compared with other areas
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Related codes
  8. Rate history
  9. Where it applies
  10. Billing questions
  11. Sources

What 50391 covers

This service delivers a therapeutic agent into the renal pelvis or ureter through an established nephrostomy or nephroureteral catheter. A urologist or interventional radiologist may perform it when medication or a chemolytic solution is needed in the upper urinary tract, such as treatment intended to dissolve selected urinary stones. It may occur in a hospital or an appropriately equipped outpatient setting. Radiologic supervision and interpretation are part of the service.

Report the code when the documented treatment is instillation through the specified catheter route, rather than needle aspiration or injection of a renal cyst or pelvis. The record should identify the agent, treatment purpose, access route, and radiologic work. The service has a 0-day global period, so same-day preoperative and postoperative care is included. 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. For bilateral performance, modifier 50 is paid at 150%. Assistant-at-surgery payment is restricted; 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.

How King County, WA compares for 50391

Across 109 of 109 payment localities, the office rate for 50391 runs from $115.55 in Arkansas to $159.16 in Alaska. King County, WA pays $141.57. The RVUs are the same everywhere; the geographic indexes change the dollars.

50391 in King County, WA vs other payment areas
  1. King County, WA · this page$141.57
  2. Rest of Washington · Washington$129.11−$12.46
  3. Los Angeles, CA · California$137.33−$4.24
  4. Washington, DC area · District of Columbia$141.48−$0.09
  5. Miami, FL · Florida$141.79+$0.22
  6. Chicago, IL · Illinois$138.36−$3.21
  7. Manhattan, NY · New York$145.02+$3.45

Other areas in Washington first, then benchmark localities. Bars start at $0.

Every other payment area

50391 in every other Medicare payment locality
Payment localityOfficeFacility
AlaskaAlaska$159.16$113.98
AlabamaAlabama$116.85$79.73
ArkansasArkansas$115.55$79.11
ArizonaArizona$124.38$83.28
Bakersfield, CACalifornia$130.66$84.17
Chico, CACalifornia$129.95$83.45
El Centro, CACalifornia$129.99$83.49
Fresno, CACalifornia$129.95$83.45

50391 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.

$115.55

$159.16

Color shows the midpoint of each state’s locality range.

View every state and territory as a table
50391 office rate range by state
State / territoryOffice rate rangeLocalities
AK$159.161
AL$116.851
AR$115.551
AZ$124.381
CA$129.95–$155.0629
CO$129.821
CT$134.491
DC$141.481
DE$126.101
FL$128.85–$141.793
GA$122.81–$129.952
GU$131.481
HI$131.481
IA$117.711
ID$118.601
IL$126.95–$138.364
IN$119.091
KS$117.961
KY$120.421
LA$120.54–$125.082
MA$129.59–$139.752
MD$127.90–$141.483
ME$119.79–$123.802
MI$123.47–$130.822
MN$123.221
MO$119.40–$124.613
MS$117.461
MT$127.241
NC$120.651
ND$122.501
NE$118.001
NH$128.531
NJ$135.69–$140.692
NM$124.271
NV$125.971
NY$122.10–$148.695
OH$122.501
OK$119.541
OR$124.65–$132.382
PA$122.27–$132.232
PR$127.751
RI$129.431
SC$121.841
SD$121.931
TN$118.501
TX$121.70–$130.398
UT$123.111
VA$123.96–$141.482
VI$127.751
VT$122.741
WA$129.11–$141.572
WI$119.381
WV$123.451
WY$125.171

See 50391 in every payment locality

How the 50391 rate is calculated

Each of 50391’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 · 50391

RVUs × geographic indexes × conversion factor

Office or facility?

Work1.91

1.91 RVUs× 1.000 GPCI

Practice expense1.66

1.66 RVUs× 1.000 GPCI

Malpractice0.24

0.24 RVUs× 1.000 GPCI

Adjusted RVUs

3.8100

Conversion factor

$33.4009

Medicare rate

$127.26

Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.

The exact King County, WA inputs and CMS source lines

PPRRVU2026_Oct_nonQPP.csv

5,913

Code
50391
Physician work
1.91
Practice expense
1.66
Malpractice
0.24

GPCI2026.csv

108

Locality
King County, WA
Physician work
1.050
Practice expense
1.227
Malpractice
0.817
Office calculation for 50391 in King County, WA
ComponentRVULocality factorAdjusted
Physician work1.91× 1.0502.0055
Practice expense1.66× 1.2272.0368
Malpractice0.24× 0.8170.1961
Total RVUs4.2384
Conversion factor× 33.4009

Office rate, King County, WA$141.57

Office: (1.91 × 1.05 + 1.66 × 1.227 + 0.24 × 0.817) × $33.4009 = $141.57

Facility: (1.91 × 1.05 + 0.39 × 1.227 + 0.24 × 0.817) × $33.4009 = $89.52

Open 50391 in the RVU calculator

Payment rules and modifiers for 50391

The CMS indicators that decide how 50391 is paid alongside other services.

CMS payment indicators · 50391

Renal instillation, through nephrostomy access

RuleCMS valueWhat it means
Global period000Same-day global: pre- and post-op care on the day of the procedure is included.
Multiple procedures2Standard reduction: highest-valued procedure at 100%, others at 50%.
Bilateral (modifier 50)1Bilateral with modifier 50 pays 150% of the fee schedule amount.
Assistant at surgery (80/81/82/AS)1Not paid (statutory restriction).
Co-surgeons (62)0Not permitted.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.

What modifiers do to the payment

Modifier 50 · payment effect

With and without the modifier

50391 without 50 · national office

$127.26

Renal instillation, through nephrostomy access

50391-50 · Bilateral: 150%

$190.89

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).

When to use modifier 50

Codes related to 50391

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

Codes related to 50391
CodeHow it relatesOffice range, King County, WA
Used instead
50390Renal lesion drainage, needle aspiration or injectionNeedle aspiration or injection of a renal cyst or pelvis, rather than catheter-based therapeutic instillation.No office rate

How 50391 has changed in King County, WA

50391 · Office / nonfacility

$141.57

Effective 2026-10-01

The base rate is $7.93 higher than on 2025-10-01, moving from $133.64 to $141.57 (5.9%).

It is unchanged from the immediately preceding available release, effective 2026-07-01.

Base rate by release · bars start at $0 · select a bar to compare

One bar per available release, ordered by effective date. Missing rates remain gaps. These comparisons hold the code, setting and locality identifiers constant; they do not isolate which policy or input caused a change.

What changed, release by release

  1. January 1, 2026

    RVU26A

    $133.64changed to$141.57

    • Conversion factor 32.3465 changed to 33.4009
    • Work RVU 1.96 changed to 1.91
    • Practice expense RVU 1.55 changed to 1.66
    • Malpractice RVU 0.23 changed to 0.24
    • Work GPCI 1.043 changed to 1.050
    • Practice expense GPCI 1.220 changed to 1.227
    • Malpractice GPCI 0.853 changed to 0.817

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $137.81changed to$133.64

    • Conversion factor 33.2875 changed to 32.3465
    • Malpractice RVU 0.24 changed to 0.23

    Held through RVU25B, RVU25C, RVU25D.

  3. March 9, 2024

    RVU24AR

    $135.56changed to$137.81

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $137.12changed to$135.56

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 1.51 changed to 1.55
    • Malpractice RVU 0.23 changed to 0.24
    • Work GPCI 1.039 changed to 1.043
    • Practice expense GPCI 1.207 changed to 1.220
    • Malpractice GPCI 0.815 changed to 0.853

  5. January 1, 2023

    RVU23A

    $138.43changed to$137.12

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 1.50 changed to 1.51
    • Work GPCI 1.036 changed to 1.039
    • Practice expense GPCI 1.194 changed to 1.207
    • Malpractice GPCI 0.776 changed to 0.815

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $140.14changed to$138.43

    • Conversion factor 34.8931 changed to 34.6062
    • Practice expense RVU 1.52 changed to 1.50
    • Malpractice RVU 0.22 changed to 0.23

    Held through RVU22B, RVU22C, RVU22D.

  7. January 1, 2021

    RVU21A

    $137.44changed to$140.14

    • Conversion factor 36.0896 changed to 34.8931
    • Practice expense RVU 1.36 changed to 1.52
    • Malpractice RVU 0.23 changed to 0.22
    • Work GPCI 1.031 changed to 1.036
    • Practice expense GPCI 1.170 changed to 1.194
    • Malpractice GPCI 0.854 changed to 0.776

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $135.50changed to$137.44

    • Conversion factor 36.0391 changed to 36.0896
    • Practice expense RVU 1.37 changed to 1.36
    • Malpractice RVU 0.19 changed to 0.23
    • Work GPCI 1.027 changed to 1.031
    • Practice expense GPCI 1.146 changed to 1.170
    • Malpractice GPCI 0.931 changed to 0.854

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $134.53changed to$135.50

    • Conversion factor 35.9996 changed to 36.0391
    • Practice expense RVU 1.35 changed to 1.37

    Held through RVU19B, RVU19C, RVU19D.

  10. January 1, 2018

    RVU18AR1

    $132.39changed to$134.53

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 1.34 changed to 1.35
    • Work GPCI 1.026 changed to 1.027
    • Practice expense GPCI 1.151 changed to 1.146
    • Malpractice GPCI 0.713 changed to 0.931

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    $130.06changed to$132.39

    • Conversion factor 35.8043 changed to 35.8887
    • Practice expense RVU 1.32 changed to 1.34
    • Malpractice RVU 0.20 changed to 0.19
    • Work GPCI 1.025 changed to 1.026
    • Practice expense GPCI 1.155 changed to 1.151
    • Malpractice GPCI 0.495 changed to 0.713

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2016

    RVU16A

    $131.12changed to$130.06

    • Conversion factor 35.9335 changed to 35.8043
    • Practice expense RVU 1.33 changed to 1.32
    • Malpractice RVU 0.21 changed to 0.20

    Held through RVU16B, RVU16C, RVU16D.

  13. July 1, 2015

    RVU15C

    $130.47changed to$131.12

    • Conversion factor 35.7547 changed to 35.9335

    Held through RVU15D.

  14. January 1, 2015

    RVU15A

    $130.62changed to$130.47

    • Conversion factor 35.8228 changed to 35.7547
    • Practice expense RVU 1.31 changed to 1.33
    • Malpractice RVU 0.19 changed to 0.21
    • Practice expense GPCI 1.150 changed to 1.155
    • Malpractice GPCI 0.688 changed to 0.495

    Held through RVU15B.

  15. January 1, 2014

    RVU14A

    $128.45changed to$130.62

    • Conversion factor 34.0230 changed to 35.8228
    • Practice expense RVU 1.39 changed to 1.31
    • Malpractice RVU 0.20 changed to 0.19
    • Practice expense GPCI 1.144 changed to 1.150
    • Malpractice GPCI 0.881 changed to 0.688

    Held through RVU14B, RVU14C, RVU14D.

  16. January 1, 2013

    RVU13AR

    Earliest loaded release: $128.45

    Held through RVU13B, RVU13C, RVU13D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$141.57$89.52RVU26D
2026-07-01$141.57$89.52RVU26C
2026-04-01$141.57$89.52RVU26B
2026-01-01$141.57$89.52RVU26A
2025-10-01$133.64$100.49RVU25D
2025-07-01$133.64$100.49RVU25C
2025-04-01$133.64$100.49RVU25B
2025-01-01$133.64$100.49RVU25A
2024-10-01$137.81$103.29RVU24D
2024-07-01$137.81$103.29RVU24C
2024-04-01$137.81$103.29RVU24B
2024-03-09$137.81$103.29RVU24AR
2024-01-01$135.56$101.61RVU24A
2023-10-01$137.12$102.77RVU23D
2023-07-01$137.12$102.77RVU23C
2023-04-01$137.12$102.77RVU23B
2023-01-01$137.12$102.77RVU23A
2022-10-01$138.43$103.72RVU22D
2022-07-01$138.43$103.72RVU22C
2022-04-01$138.43$103.72RVU22B
2022-01-01$138.43$103.72RVU22A
2021-10-01$140.14$104.72RVU21D
2021-07-01$140.14$104.72RVU21C
2021-04-01$140.14$104.72RVU21B
2021-01-01$140.14$104.72RVU21A
2020-10-01$137.44$107.89RVU20D
2020-07-01$137.44$107.89RVU20C
2020-04-01$137.44$107.89RVU20B
2020-01-01$137.44$107.89RVU20A
2019-10-01$135.50$107.42RVU19D
2019-07-01$135.50$107.42RVU19C
2019-04-01$135.50$107.42RVU19B
2019-01-01$135.50$107.42RVU19A
2018-10-01$134.53$107.30RVU18D
2018-07-01$134.53$107.30RVU18C
2018-04-01$134.53$107.30RVU18B
2018-01-01$134.53$107.30RVU18AR1
2017-10-01$132.39$105.12RVU17D
2017-07-01$132.39$105.12RVU17C
2017-04-01$132.39$105.12RVU17B
2017-01-01$132.39$105.12RVU17A
2016-10-01$130.06$102.77RVU16D
2016-07-01$130.06$102.77RVU16C
2016-04-01$130.06$102.77RVU16B
2016-01-01$130.06$102.77RVU16A
2015-10-01$131.12$104.15RVU15D
2015-07-01$131.12$104.15RVU15C
2015-04-01$130.47$103.63RVU15B
2015-01-01$130.47$103.63RVU15A
2014-10-01$130.62$103.84RVU14D
2014-07-01$130.62$103.84RVU14C
2014-04-01$130.62$103.84RVU14B
2014-01-01$130.62$103.84RVU14A
2013-10-01$128.45$101.20RVU13D
2013-07-01$128.45$101.20RVU13C
2013-04-01$128.45$101.20RVU13B
2013-01-01$128.45$101.20RVU13AR

Price 50391 for an earlier date of service

Where the King County, WA rate applies

King County, WA is a Medicare payment area, not a city. Our Census mapping connects it to 63 cities and communities in Washington. Some span more than one payment area; confirm with the service ZIP.

  • Seattle
  • Algona
  • Ames Lake
  • 50391 in Auburn · multiple payment areas
  • Baring
  • Beaux Arts Village
  • Bellevue
  • Black Diamond

Browse all communities in Washington

50391 billing questions

When should this code be used instead of 50390?

Use 50391 for therapeutic delivery through a nephrostomy or nephroureteral catheter. Code 50390 describes percutaneous needle aspiration or injection of a renal cyst or pelvis.

Is radiologic supervision and interpretation separately reported?

No. Radiologic supervision and interpretation are included in this service.

What documentation supports the service?

Document the therapeutic agent, the clinical purpose, delivery through nephrostomy or nephroureteral access, and the associated radiologic work.

How is bilateral performance reported?

CMS identifies this as a bilateral procedure; modifier 50 is paid at 150%.

Can an assistant or co-surgeon be reported?

Assistant-at-surgery payment is restricted. Co-surgeons and team surgery are not permitted for this service.

How does the 0-day global period affect same-day care?

Same-day preoperative and postoperative care is included in the procedure's 0-day 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
RVUs for 50391PPRRVU2026_Oct_nonQPP.csv, line 5,913 (RVU26D)
Geographic factors for King County, WAGPCI2026.csv, line 108 (RVU26D)

Open CMS sourceHow we calculate rates

Did this answer your question about what 50391 pays in King County, WA?

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

Fee sheets · Coming soon

Put 50391 and the rest of your codes on one sheet

Your codes at your locality, with payer contracts beside Medicare.

Join the waitlist