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CPT code 88189: Flow cytometry, 16 or more markers2026 Medicare rate & RVUs in Riverside, CA

Reports the professional interpretation of a flow cytometry study using 16 or more markers, commonly for immunophenotyping blood, marrow, tissue, or fluid specimens.

CMS RVU26DEffective Oct 1, 2026One payment locality265.5K Medicare services in 2024

In Riverside, CA, Medicare pays $81.87 for 88189 in the office and $81.87 when it’s performed in a hospital or facility.

$81.87Office (non-facility)
$81.87Hospital or facility
+3.4%vs the national office rate ($79.16)

Check a contract rate as a % of Medicare · 88189 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 88189 for the payment locality that covers the ZIP.

On this page 11 sections
  1. Rate in Riverside, CA
  2. What 88189 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 88189 covers

A pathologist or other qualified physician interprets flow cytometry findings from a study using 16 or more markers and prepares the interpretive report. These studies commonly support evaluation of suspected hematologic malignancies, such as leukemia or lymphoma, using specimens such as peripheral blood, bone marrow, lymph node tissue, or body fluids. The interpretation assesses the marker findings as a whole rather than billing for the laboratory work that processes and analyzes the specimen.

Select this level according to the number of markers in the study: 88189 is for 16 or more, while 88187 and 88188 cover lower marker ranges. The record should support the marker count and include the signed interpretation and report. This is a professional-component-only code; separate code or codes cover the technical portion. The technical services may include 88184 for the first marker and 88185 for additional markers, as appropriate.

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 Riverside, CA compares for 88189

Across 109 of 109 payment localities, the office rate for 88189 runs from $75.01 in Arkansas to $107.22 in Alaska. Riverside, CA pays $81.87. The RVUs are the same everywhere; the geographic indexes change the dollars.

88189 in Riverside, CA vs other payment areas
  1. Riverside, CA · this page$81.87
  2. Bakersfield, CA · California$81.35−$0.52
  3. Chico, CA · California$81.07−$0.80
  4. El Centro, CA · California$81.08−$0.79
  5. Fresno, CA · California$81.07−$0.80
  6. Hanford, CA · California$81.07−$0.80
  7. Los Angeles, CA · California$84.56+$2.69

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

Every other payment area

88189 in every other Medicare payment locality
Payment localityOfficeFacility
Madera, CACalifornia$81.07$81.07
Merced, CACalifornia$81.07$81.07
Modesto, CACalifornia$81.07$81.07
Napa, CACalifornia$88.30$88.30
Oxnard, CACalifornia$83.72$83.72
Redding, CACalifornia$81.07$81.07
Rest of CaliforniaCalifornia$81.07$81.07
Sacramento, CACalifornia$83.56$83.56

88189 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.

$75.01

$107.22

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

View every state and territory as a table
88189 office rate range by state
State / territoryOffice rate rangeLocalities
AK$107.221
AL$75.471
AR$75.011
AZ$78.161
CA$81.07–$93.6229
CO$80.681
CT$82.411
DC$86.221
DE$78.941
FL$79.40–$83.613
GA$77.30–$80.142
GU$81.101
HI$81.101
IA$75.931
ID$76.221
IL$78.62–$82.684
IN$76.401
KS$75.951
KY$76.591
LA$76.60–$78.222
MA$80.71–$85.322
MD$79.78–$86.223
ME$76.57–$78.102
MI$77.60–$80.022
MN$78.131
MO$76.15–$78.143
MS$75.581
MT$79.161
NC$76.881
ND$77.771
NE$76.061
NH$79.741
NJ$83.57–$86.232
NM$77.861
NV$78.791
NY$77.40–$88.755
OH$77.321
OK$76.351
OR$78.38–$81.822
PA$77.28–$81.492
PR$79.361
RI$80.671
SC$77.181
SD$77.611
TN$76.131
TX$77.07–$80.338
UT$77.641
VA$78.11–$86.222
VI$79.361
VT$77.791
WA$80.46–$86.362
WI$76.641
WV$77.371
WY$78.551

See 88189 in every payment locality

How the 88189 rate is calculated

Each of 88189’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 · 88189

RVUs × geographic indexes × conversion factor

Office or facility?

Work1.66

1.66 RVUs× 1.000 GPCI

Practice expense0.64

0.64 RVUs× 1.000 GPCI

Malpractice0.07

0.07 RVUs× 1.000 GPCI

Adjusted RVUs

2.3700

Conversion factor

$33.4009

Medicare rate

$79.16

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

The exact Riverside, CA inputs and CMS source lines

PPRRVU2026_Oct_nonQPP.csv

11,166

Code
88189
Physician work
1.66
Practice expense
0.64
Malpractice
0.07

GPCI2026.csv

20

Locality
Riverside, CA
Physician work
1.018
Practice expense
1.096
Malpractice
0.853
Office calculation for 88189 in Riverside, CA
ComponentRVULocality factorAdjusted
Physician work1.66× 1.0181.6899
Practice expense0.64× 1.0960.7014
Malpractice0.07× 0.8530.0597
Total RVUs2.4510
Conversion factor× 33.4009

Office rate, Riverside, CA$81.87

Office: (1.66 × 1.018 + 0.64 × 1.096 + 0.07 × 0.853) × $33.4009 = $81.87

Facility: (1.66 × 1.018 + 0.64 × 1.096 + 0.07 × 0.853) × $33.4009 = $81.87

Open 88189 in the RVU calculator

Payment rules and modifiers for 88189

The CMS indicators that decide how 88189 is paid alongside other services.

CMS payment indicators · 88189

Flow cytometry, 16 or more markers

RuleCMS valueWhat it means
Global periodXXXThe global surgery concept doesn’t apply.
Multiple procedures0No multiple-procedure reduction.
Bilateral (modifier 50)0The 150% bilateral adjustment doesn’t apply.
Assistant at surgery (80/81/82/AS)0Not paid without supporting documentation.
Co-surgeons (62)0Not permitted.
Team surgery (66)0Not permitted.
Professional/technical2Professional component only.

Codes related to 88189

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

Codes related to 88189
CodeHow it relatesOffice range, Riverside, CA
Same family
88187Flow cytometry, 2–8 marker interpretationProfessional interpretation for a flow cytometry study using a lower marker range.$36.32
88188Flow cytometry, 9–15 markersProfessional interpretation for 9 through 15 markers; 88189 begins at 16.$60.53
Often billed with
88184Flow cytometry, first marker, technical componentMay report the technical portion for the study's first marker.$88.79
88185Flow cytometry add-on, technical work, each additional markerMay report technical work for additional markers.$25.26

How 88189 has changed in Riverside, CA

88189 · Office / nonfacility

$81.87

Effective 2026-10-01

The base rate is $0.05 higher than on 2025-10-01, moving from $81.82 to $81.87 (0.1%).

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

    $81.82changed to$81.87

    • Conversion factor 32.3465 changed to 33.4009
    • Work RVU 1.70 changed to 1.66
    • Practice expense RVU 0.68 changed to 0.64
    • Work GPCI 1.014 changed to 1.018
    • Practice expense GPCI 1.093 changed to 1.096
    • Malpractice GPCI 0.892 changed to 0.853

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $84.13changed to$81.82

    • Conversion factor 33.2875 changed to 32.3465
    • Practice expense RVU 0.67 changed to 0.68
    • Malpractice RVU 0.08 changed to 0.07

    Held through RVU25B, RVU25C, RVU25D.

  3. March 9, 2024

    RVU24AR

    $82.76changed to$84.13

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $86.19changed to$82.76

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 0.68 changed to 0.67
    • Work GPCI 1.021 changed to 1.014
    • Practice expense GPCI 1.079 changed to 1.093
    • Malpractice GPCI 0.924 changed to 0.892

  5. January 1, 2023

    RVU23A

    $87.35changed to$86.19

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 0.65 changed to 0.68
    • Malpractice RVU 0.09 changed to 0.08
    • Work GPCI 1.027 changed to 1.021
    • Practice expense GPCI 1.065 changed to 1.079
    • Malpractice GPCI 0.955 changed to 0.924

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $87.89changed to$87.35

    • Conversion factor 34.8931 changed to 34.6062
    • Malpractice GPCI 0.896 changed to 0.955

    Held through RVU22B, RVU22C, RVU22D.

  7. January 1, 2021

    RVU21A

    $91.39changed to$87.89

    • Conversion factor 36.0896 changed to 34.8931
    • Practice expense RVU 0.67 changed to 0.65
    • Work GPCI 1.024 changed to 1.027
    • Practice expense GPCI 1.070 changed to 1.065
    • Malpractice GPCI 0.830 changed to 0.896

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $90.66changed to$91.39

    • Conversion factor 36.0391 changed to 36.0896
    • Malpractice RVU 0.08 changed to 0.09
    • Work GPCI 1.021 changed to 1.024
    • Practice expense GPCI 1.074 changed to 1.070
    • Malpractice GPCI 0.753 changed to 0.830

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $91.09changed to$90.66

    • Conversion factor 35.9996 changed to 36.0391
    • Practice expense RVU 0.69 changed to 0.67
    • Work GPCI 1.020 changed to 1.021
    • Malpractice GPCI 0.689 changed to 0.753

    Held through RVU19B, RVU19C, RVU19D.

  10. January 1, 2018

    RVU18AR1

    $95.25changed to$91.09

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 0.80 changed to 0.69
    • Work GPCI 1.024 changed to 1.020
    • Practice expense GPCI 1.079 changed to 1.074
    • Malpractice GPCI 0.626 changed to 0.689

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    No ratechanged to$95.25

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2013

    RVU13AR

    Earliest loaded release: No rate

    Held through RVU13B, RVU13C, RVU13D, RVU14A, RVU14B, RVU14C, RVU14D, RVU15A, RVU15B, RVU15C, RVU15D, RVU16A, RVU16B, RVU16C, RVU16D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$81.87$81.87RVU26D
2026-07-01$81.87$81.87RVU26C
2026-04-01$81.87$81.87RVU26B
2026-01-01$81.87$81.87RVU26A
2025-10-01$81.82$81.82RVU25D
2025-07-01$81.82$81.82RVU25C
2025-04-01$81.82$81.82RVU25B
2025-01-01$81.82$81.82RVU25A
2024-10-01$84.13$84.13RVU24D
2024-07-01$84.13$84.13RVU24C
2024-04-01$84.13$84.13RVU24B
2024-03-09$84.13$84.13RVU24AR
2024-01-01$82.76$82.76RVU24A
2023-10-01$86.19$86.19RVU23D
2023-07-01$86.19$86.19RVU23C
2023-04-01$86.19$86.19RVU23B
2023-01-01$86.19$86.19RVU23A
2022-10-01$87.35$87.35RVU22D
2022-07-01$87.35$87.35RVU22C
2022-04-01$87.35$87.35RVU22B
2022-01-01$87.35$87.35RVU22A
2021-10-01$87.89$87.89RVU21D
2021-07-01$87.89$87.89RVU21C
2021-04-01$87.89$87.89RVU21B
2021-01-01$87.89$87.89RVU21A
2020-10-01$91.39$91.39RVU20D
2020-07-01$91.39$91.39RVU20C
2020-04-01$91.39$91.39RVU20B
2020-01-01$91.39$91.39RVU20A
2019-10-01$90.66$90.66RVU19D
2019-07-01$90.66$90.66RVU19C
2019-04-01$90.66$90.66RVU19B
2019-01-01$90.66$90.66RVU19A
2018-10-01$91.09$91.09RVU18D
2018-07-01$91.09$91.09RVU18C
2018-04-01$91.09$91.09RVU18B
2018-01-01$91.09$91.09RVU18AR1
2017-10-01$95.25$95.25RVU17D
2017-07-01$95.25$95.25RVU17C
2017-04-01$95.25$95.25RVU17B
2017-01-01$95.25$95.25RVU17A
2016-10-01Rate data unavailableRate data unavailableRVU16D
2016-07-01Rate data unavailableRate data unavailableRVU16C
2016-04-01Rate data unavailableRate data unavailableRVU16B
2016-01-01Rate data unavailableRate data unavailableRVU16A
2015-10-01Rate data unavailableRate data unavailableRVU15D
2015-07-01Rate data unavailableRate data unavailableRVU15C
2015-04-01Rate data unavailableRate data unavailableRVU15B
2015-01-01Rate data unavailableRate data unavailableRVU15A
2014-10-01Rate data unavailableRate data unavailableRVU14D
2014-07-01Rate data unavailableRate data unavailableRVU14C
2014-04-01Rate data unavailableRate data unavailableRVU14B
2014-01-01Rate data unavailableRate data unavailableRVU14A
2013-10-01Rate data unavailableRate data unavailableRVU13D
2013-07-01Rate data unavailableRate data unavailableRVU13C
2013-04-01Rate data unavailableRate data unavailableRVU13B
2013-01-01Rate data unavailableRate data unavailableRVU13AR

Price 88189 for an earlier date of service

Where the Riverside, CA rate applies

Riverside, CA is a Medicare payment area, not a city. Our Census mapping connects it to 127 cities and communities in California. Some span more than one payment area; confirm with the service ZIP.

  • Ontario
  • Riverside
  • San Bernardino
  • Adelanto
  • Aguanga
  • Anza
  • Apple Valley
  • Baker

Browse all communities in California

88189 billing questions

When should 88189 be selected instead of 88188?

Use 88189 when the flow cytometry study includes 16 or more markers. Code 88188 is for the lower range of 9 through 15 markers.

Does 88189 include the laboratory's technical work?

No. It represents the professional interpretation and report; separate code or codes cover the technical portion.

Which codes may represent the technical portion?

Code 88184 covers the technical work for the first marker, and 88185 covers additional markers, as appropriate to the study.

What documentation supports reporting 88189?

Keep the flow cytometry report, the marker count supporting the 16-or-more level, and the signed professional interpretation.

Should modifier 26 be appended to 88189?

No. 88189 is already a professional-component-only code.

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 88189PPRRVU2026_Oct_nonQPP.csv, line 11,166 (RVU26D)
Geographic factors for Riverside, CAGPCI2026.csv, line 20 (RVU26D)

Open CMS sourceHow we calculate rates

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