CPT code 88366: FISH interpretation, interpretation and report2026 Medicare rate & RVUs in Oxnard, CA

Reports the diagnostic interpretation of in situ hybridization findings, such as fluorescent probe results in tumor tissue, for a specific clinical question.

CMS RVU26DEffective Oct 1, 2026One payment locality3.2K Medicare services in 2024

In Oxnard, CA, Medicare pays $306.50 for 88366 in the office.

$306.50Office (non-facility)
Not available in this settingHospital or facility
+15.6%vs the national office rate ($265.20)

Check a contract rate as a % of Medicare · 88366 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 88366 for the payment locality that covers the ZIP.

On this page 11 sections
  1. Rate in Oxnard, CA
  2. What 88366 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 88366 covers

A pathologist evaluates in situ hybridization findings, including fluorescent in situ hybridization (FISH) signals in tissue or cytology specimens, and prepares a diagnostic interpretation and report. Oncology specimens may be assessed for gene or chromosome changes relevant to tumor classification or treatment decisions. The report connects the probe findings with the specimen and clinical question; this service is distinct from performing the probe-staining procedure itself.

Report 88366 for the interpretation and report associated with an in situ hybridization study, supported by documentation identifying the specimen, test findings, and diagnostic conclusion. CMS recognizes professional and technical components: modifier 26 identifies the professional interpretation, modifier TC identifies the technical service, and billing without either modifier represents the global service. The professional component reflects the physician’s interpretation; the technical component covers equipment and staff involved in the test.

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 Oxnard, CA compares for 88366

Across 109 of 109 payment localities, the office rate for 88366 runs from $233.05 in Arkansas to $367.79 in San Benito County, CA. Oxnard, CA pays $306.50. The RVUs are the same everywhere; the geographic indexes change the dollars.

88366 in Oxnard, CA vs other payment areas
  1. Oxnard, CA · this page$306.50
  2. Bakersfield, CA · California$286.90−$19.60
  3. Chico, CA · California$286.72−$19.78
  4. El Centro, CA · California$286.73−$19.77
  5. Fresno, CA · California$286.72−$19.78
  6. Hanford, CA · California$286.72−$19.78
  7. Los Angeles, CA · California$307.30+$0.80

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

Every other payment area

88366 in every other Medicare payment locality
Payment localityOfficeFacility
Madera, CACalifornia$286.72—
Merced, CACalifornia$286.72—
Modesto, CACalifornia$286.72—
Napa, CACalifornia$338.15—
Redding, CACalifornia$286.72—
Rest of CaliforniaCalifornia$286.72—
Riverside, CACalifornia$287.19—
Sacramento, CACalifornia$302.46—

88366 rates by state

Office rate range in each state. Select a state to see its payment localities.

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.

$233.05

$327.26

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

View every state and territory as a table
88366 office rate range by state
State / territoryOffice rate rangeLocalities
AK$299.341
AL$236.691
AR$233.051
AZ$258.081
CA$286.72–$367.7929
CO$279.701
CT$283.501
DC$307.311
DE$262.591
FL$256.04–$276.413
GA$241.33–$269.172
GU$295.251
HI$295.251
IA$245.401
ID$246.621
IL$246.52–$272.554
IN$248.201
KS$243.091
KY$240.291
LA$239.45–$252.202
MA$277.42–$310.062
MD$268.18–$307.313
ME$246.82–$262.702
MI$245.94–$258.302
MN$270.741
MO$234.33–$254.483
MS$233.791
MT$265.201
NC$249.751
ND$264.411
NE$247.171
NH$274.201
NJ$287.51–$303.592
NM$246.931
NV$265.201
NY$253.63–$311.175
OH$245.771
OK$241.001
OR$263.91–$290.312
PA$246.81–$275.352
PR$267.641
RI$273.201
SC$248.021
SD$264.321
TN$244.251
TX$245.00–$278.098
UT$251.661
VA$261.01–$307.312
VI$267.641
VT$262.311
WA$277.25–$317.702
WI$254.891
WV$236.511
WY$264.861

See 88366 in every payment locality

How the 88366 rate is calculated

Each of 88366’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 · 88366

RVUs × geographic indexes × conversion factor

Office or facility?

Work1.21

1.21 RVUs× 1.000 GPCI

Practice expense6.69

6.69 RVUs× 1.000 GPCI

Malpractice0.04

0.04 RVUs× 1.000 GPCI

Adjusted RVUs

7.9400

Conversion factor

$33.4009

Medicare rate

$265.20

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

The exact Oxnard, CA inputs and CMS source lines

PPRRVU2026_Oct_nonQPP.csv

11,291

Code
88366
Physician work
1.21
Practice expense
6.69
Malpractice
0.04

GPCI2026.csv

18

Locality
Oxnard, CA
Physician work
1.028
Practice expense
1.182
Malpractice
0.623
Office calculation for 88366 in Oxnard, CA
ComponentRVULocality factorAdjusted
Physician work1.21× 1.0281.2439
Practice expense6.69× 1.1827.9076
Malpractice0.04× 0.6230.0249
Total RVUs9.1764
Conversion factor× 33.4009

Office rate, Oxnard, CA$306.50

Office: (1.21 × 1.028 + 6.69 × 1.182 + 0.04 × 0.623) × $33.4009 = $306.50

Open 88366 in the RVU calculator

Payment rules and modifiers for 88366

The CMS indicators that decide how 88366 is paid alongside other services.

CMS payment indicators · 88366

FISH interpretation, interpretation and report

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/technical1Diagnostic test with separate professional (26) and technical (TC) components.

What modifiers do to the payment

Modifier 26 · payment effect

With and without the modifier

88366 without 26 · national office

$265.20

FISH interpretation, interpretation and report

88366-26 · Professional component

$57.78

Pays only the interpretation and report.

When to use modifier 26

How 88366 has changed in Oxnard, CA

88366 · Office / nonfacility

$306.50

Effective 2026-10-01

The base rate is $6.00 higher than on 2025-10-01, moving from $300.50 to $306.50 (2.0%).

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

    $300.50changed to$306.50

    • Conversion factor 32.3465 changed to 33.4009
    • Work RVU 1.24 changed to 1.21
    • Practice expense RVU 6.75 changed to 6.69
    • Malpractice RVU 0.05 changed to 0.04
    • Work GPCI 1.026 changed to 1.028
    • Practice expense GPCI 1.183 changed to 1.182
    • Malpractice GPCI 0.651 changed to 0.623

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $313.75changed to$300.50

    • Conversion factor 33.2875 changed to 32.3465
    • Practice expense RVU 6.87 changed to 6.75
    • Malpractice RVU 0.04 changed to 0.05

    Held through RVU25B, RVU25C, RVU25D.

  3. March 9, 2024

    RVU24AR

    $308.63changed to$313.75

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $325.43changed to$308.63

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 7.03 changed to 6.87
    • Work GPCI 1.027 changed to 1.026
    • Practice expense GPCI 1.181 changed to 1.183
    • Malpractice GPCI 0.689 changed to 0.651
  5. January 1, 2023

    RVU23A

    $334.35changed to$325.43

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 7.09 changed to 7.03
    • Practice expense GPCI 1.179 changed to 1.181
    • Malpractice GPCI 0.726 changed to 0.689

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $338.77changed to$334.35

    • Conversion factor 34.8931 changed to 34.6062
    • Practice expense RVU 7.13 changed to 7.09

    Held through RVU22B, RVU22C, RVU22D.

  7. January 1, 2021

    RVU21A

    $324.11changed to$338.77

    • Conversion factor 36.0896 changed to 34.8931
    • Practice expense RVU 6.52 changed to 7.13
    • Work GPCI 1.026 changed to 1.027
    • Practice expense GPCI 1.178 changed to 1.179
    • Malpractice GPCI 0.700 changed to 0.726

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $307.80changed to$324.11

    • Conversion factor 36.0391 changed to 36.0896
    • Practice expense RVU 6.16 changed to 6.52
    • Work GPCI 1.024 changed to 1.026
    • Practice expense GPCI 1.176 changed to 1.178
    • Malpractice GPCI 0.673 changed to 0.700

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $307.89changed to$307.80

    • Conversion factor 35.9996 changed to 36.0391
    • Practice expense RVU 6.17 changed to 6.16

    Held through RVU19B, RVU19C, RVU19D.

  10. January 1, 2018

    RVU18AR1

    $299.18changed to$307.89

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 5.97 changed to 6.17
    • Work GPCI 1.027 changed to 1.024
    • Practice expense GPCI 1.178 changed to 1.176
    • Malpractice GPCI 0.754 changed to 0.673

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    $303.38changed to$299.18

    • Conversion factor 35.8043 changed to 35.8887
    • Practice expense RVU 6.07 changed to 5.97
    • Work GPCI 1.030 changed to 1.027
    • Practice expense GPCI 1.180 changed to 1.178
    • Malpractice GPCI 0.834 changed to 0.754

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2016

    RVU16A

    $269.95changed to$303.38

    • Conversion factor 35.9335 changed to 35.8043
    • Practice expense RVU 5.27 changed to 6.07
    • Malpractice RVU 0.02 changed to 0.04

    Held through RVU16B, RVU16C, RVU16D.

  13. July 1, 2015

    RVU15C

    $169.46changed to$269.95

    • Conversion factor 35.7547 changed to 35.9335
    • Practice expense RVU 2.92 changed to 5.27

    Held through RVU15D.

  14. January 1, 2015

    RVU15A

    No ratechanged to$169.46

    Held through RVU15B.

  15. January 1, 2013

    RVU13AR

    Earliest loaded release: No rate

    Held through RVU13B, RVU13C, RVU13D, RVU14A, RVU14B, RVU14C, RVU14D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$306.50Not available in this settingRVU26D
2026-07-01$306.50Not available in this settingRVU26C
2026-04-01$306.50Not available in this settingRVU26B
2026-01-01$306.50Not available in this settingRVU26A
2025-10-01$300.50Not available in this settingRVU25D
2025-07-01$300.50Not available in this settingRVU25C
2025-04-01$300.50Not available in this settingRVU25B
2025-01-01$300.50Not available in this settingRVU25A
2024-10-01$313.75Not available in this settingRVU24D
2024-07-01$313.75Not available in this settingRVU24C
2024-04-01$313.75Not available in this settingRVU24B
2024-03-09$313.75Not available in this settingRVU24AR
2024-01-01$308.63Not available in this settingRVU24A
2023-10-01$325.43Not available in this settingRVU23D
2023-07-01$325.43Not available in this settingRVU23C
2023-04-01$325.43Not available in this settingRVU23B
2023-01-01$325.43Not available in this settingRVU23A
2022-10-01$334.35Not available in this settingRVU22D
2022-07-01$334.35Not available in this settingRVU22C
2022-04-01$334.35Not available in this settingRVU22B
2022-01-01$334.35Not available in this settingRVU22A
2021-10-01$338.77Not available in this settingRVU21D
2021-07-01$338.77Not available in this settingRVU21C
2021-04-01$338.77Not available in this settingRVU21B
2021-01-01$338.77Not available in this settingRVU21A
2020-10-01$324.11Not available in this settingRVU20D
2020-07-01$324.11Not available in this settingRVU20C
2020-04-01$324.11Not available in this settingRVU20B
2020-01-01$324.11Not available in this settingRVU20A
2019-10-01$307.80Not available in this settingRVU19D
2019-07-01$307.80Not available in this settingRVU19C
2019-04-01$307.80Not available in this settingRVU19B
2019-01-01$307.80Not available in this settingRVU19A
2018-10-01$307.89Not available in this settingRVU18D
2018-07-01$307.89Not available in this settingRVU18C
2018-04-01$307.89Not available in this settingRVU18B
2018-01-01$307.89Not available in this settingRVU18AR1
2017-10-01$299.18Not available in this settingRVU17D
2017-07-01$299.18Not available in this settingRVU17C
2017-04-01$299.18Not available in this settingRVU17B
2017-01-01$299.18Not available in this settingRVU17A
2016-10-01$303.38Not available in this settingRVU16D
2016-07-01$303.38Not available in this settingRVU16C
2016-04-01$303.38Not available in this settingRVU16B
2016-01-01$303.38Not available in this settingRVU16A
2015-10-01$269.95Not available in this settingRVU15D
2015-07-01$269.95Not available in this settingRVU15C
2015-04-01$169.46Not available in this settingRVU15B
2015-01-01$169.46Not available in this settingRVU15A
2014-10-01Not in this releaseNot in this releaseRVU14D
2014-07-01Not in this releaseNot in this releaseRVU14C
2014-04-01Not in this releaseNot in this releaseRVU14B
2014-01-01Not in this releaseNot in this releaseRVU14A
2013-10-01Not in this releaseNot in this releaseRVU13D
2013-07-01Not in this releaseNot in this releaseRVU13C
2013-04-01Not in this releaseNot in this releaseRVU13B
2013-01-01Not in this releaseNot in this releaseRVU13AR

Price 88366 for an earlier date of service

Where the Oxnard, CA rate applies

Oxnard, CA is a Medicare payment area, not a city. Our Census mapping connects it to 26 cities and communities in California. Some span more than one payment area; confirm with the service ZIP.

  • Oxnard
  • Thousand Oaks
  • Bell Canyon
  • Camarillo
  • Casa Conejo
  • Channel Islands Beach
  • El Rio
  • Fillmore

Browse all communities in California

88366 billing questions

How does 88366 differ from the probe-staining codes?

88366 represents interpretation and reporting of in situ hybridization findings. Codes such as 88364 and 88367 describe probe-staining procedures, including whether the procedure is automated.

Can the professional and technical portions be billed separately?

Yes. Modifier 26 identifies the professional interpretation and modifier TC identifies the technical service. Without either modifier, the claim represents the global service.

What documentation supports 88366?

The record should identify the specimen and in situ hybridization findings and include the diagnostic interpretation and report. The report should make clear the clinical conclusion drawn from the probe results.

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 88366PPRRVU2026_Oct_nonQPP.csv, line 11,291 (RVU26D)
Geographic factors for Oxnard, CAGPCI2026.csv, line 18 (RVU26D)

Open CMS sourceHow we calculate rates

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