CPT code 88319: Enzyme histochemistry, each specimen2026 Medicare rate & RVUs in Idaho

Reports enzyme histochemical analysis of a tissue specimen, often in muscle biopsy workups where demonstrating enzyme activity helps characterize a disorder.

CMS RVU26DEffective Oct 1, 2026One payment locality12.4K Medicare services in 2024

In Idaho, Medicare pays $122.32 for 88319 in the office.

$122.32Office (non-facility)
Not available in this settingHospital or facility
−7.3%vs the national office rate ($131.93)

Check a contract rate as a % of Medicare · 88319 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 88319 for the payment locality that covers the ZIP.

On this page 11 sections
  1. Rate in Idaho
  2. What 88319 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 88319 covers

Enzyme histochemistry uses stains to demonstrate enzyme activity in tissue, supporting evaluation of suspected metabolic or neuromuscular disease. A common setting is a muscle biopsy workup, where a pathology laboratory processes tissue and a pathologist interprets the staining pattern. The service is reported for each specimen analyzed, rather than for each individual stain applied to that specimen.

Select the code when the documented work specifically evaluates tissue enzyme activity. The pathology report and laboratory record should identify the specimen and findings that support the enzyme study. Medicare recognizes professional and technical components: modifier 26 identifies the interpretation, modifier TC identifies the laboratory work, and billing without either modifier represents the global service.

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 Idaho compares for 88319

Across 109 of 109 payment localities, the office rate for 88319 runs from $115.44 in Arkansas to $183.57 in San Benito County, CA. Idaho pays $122.32. The RVUs are the same everywhere; the geographic indexes change the dollars.

88319 in Idaho vs other payment areas
  1. Idaho · this page$122.32
  2. Los Angeles, CA · California$153.09+$30.77
  3. Washington, DC area · District of Columbia$153.20+$30.88
  4. Miami, FL · Florida$138.12+$15.80
  5. Chicago, IL · Illinois$133.92+$11.60
  6. Manhattan, NY · New York$152.03+$29.71
  7. Alaska · Alaska$147.55+$25.23

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

Every other payment area

88319 in every other Medicare payment locality
Payment localityOfficeFacility
AlabamaAlabama$117.30—
ArkansasArkansas$115.44—
ArizonaArizona$128.27—
Bakersfield, CACalifornia$142.77—
Chico, CACalifornia$142.67—
El Centro, CACalifornia$142.67—
Fresno, CACalifornia$142.67—
Hanford, CACalifornia$142.67—

88319 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.

$115.44

$163.12

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

View every state and territory as a table
88319 office rate range by state
State / territoryOffice rate rangeLocalities
AK$147.551
AL$117.301
AR$115.441
AZ$128.271
CA$142.67–$183.5729
CO$139.191
CT$141.241
DC$153.201
DE$130.561
FL$127.44–$138.123
GA$119.86–$134.002
GU$147.071
HI$147.071
IA$121.681
ID$122.321
IL$122.62–$135.894
IN$123.131
KS$120.531
KY$119.241
LA$118.83–$125.372
MA$138.03–$154.572
MD$133.39–$153.203
ME$122.47–$130.542
MI$122.18–$128.652
MN$134.521
MO$116.24–$126.483
MS$115.891
MT$131.931
NC$123.961
ND$131.341
NE$122.571
NH$136.461
NJ$143.17–$151.272
NM$122.711
NV$131.881
NY$125.96–$155.375
OH$122.061
OK$119.561
OR$131.18–$144.562
PA$122.57–$137.102
PR$133.171
RI$135.901
SC$123.151
SD$131.271
TN$121.141
TX$121.64–$138.448
UT$125.021
VA$129.71–$153.202
VI$133.171
VT$130.301
WA$137.94–$158.402
WI$126.471
WV$117.491
WY$131.671

See 88319 in every payment locality

How the 88319 rate is calculated

Each of 88319’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 · 88319

RVUs × geographic indexes × conversion factor

Office or facility?

Work0.52

0.52 RVUs× 1.000 GPCI

Practice expense3.40

3.40 RVUs× 1.000 GPCI

Malpractice0.03

0.03 RVUs× 1.000 GPCI

Adjusted RVUs

3.9500

Conversion factor

$33.4009

Medicare rate

$131.93

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

The exact Idaho inputs and CMS source lines

PPRRVU2026_Oct_nonQPP.csv

11,227

Code
88319
Physician work
0.52
Practice expense
3.40
Malpractice
0.03

GPCI2026.csv

47

Locality
Idaho
Physician work
1.000
Practice expense
0.920
Malpractice
0.473
Office calculation for 88319 in Idaho
ComponentRVULocality factorAdjusted
Physician work0.52× 1.0000.5200
Practice expense3.40× 0.9203.1280
Malpractice0.03× 0.4730.0142
Total RVUs3.6622
Conversion factor× 33.4009

Office rate, Idaho$122.32

Office: (0.52 × 1 + 3.4 × 0.92 + 0.03 × 0.473) × $33.4009 = $122.32

Open 88319 in the RVU calculator

Payment rules and modifiers for 88319

The CMS indicators that decide how 88319 is paid alongside other services.

CMS payment indicators · 88319

Enzyme histochemistry, each specimen

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

88319 without 26 · national office

$131.93

Enzyme histochemistry, each specimen

88319-26 · Professional component

$25.38

Pays only the interpretation and report.

When to use modifier 26

How 88319 has changed in Idaho

88319 · Office / nonfacility

$122.32

Effective 2026-10-01

The base rate is $1.93 higher than on 2025-10-01, moving from $120.39 to $122.32 (1.6%).

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

    $120.39changed to$122.32

    • Conversion factor 32.3465 changed to 33.4009
    • Work RVU 0.53 changed to 0.52
    • Practice expense RVU 3.50 changed to 3.40
    • Practice expense GPCI 0.908 changed to 0.920
    • Malpractice GPCI 0.461 changed to 0.473

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $125.10changed to$120.39

    • Conversion factor 33.2875 changed to 32.3465
    • Practice expense RVU 3.54 changed to 3.50

    Held through RVU25B, RVU25C, RVU25D.

  3. March 9, 2024

    RVU24AR

    $123.06changed to$125.10

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $123.72changed to$123.06

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 3.48 changed to 3.54
    • Practice expense GPCI 0.893 changed to 0.908
    • Malpractice GPCI 0.439 changed to 0.461
  5. January 1, 2023

    RVU23A

    $126.51changed to$123.72

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 3.55 changed to 3.48
    • Practice expense GPCI 0.877 changed to 0.893
    • Malpractice GPCI 0.416 changed to 0.439

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $115.93changed to$126.51

    • Conversion factor 34.8931 changed to 34.6062
    • Practice expense RVU 3.17 changed to 3.55

    Held through RVU22B, RVU22C, RVU22D.

  7. January 1, 2021

    RVU21A

    $102.97changed to$115.93

    • Conversion factor 36.0896 changed to 34.8931
    • Practice expense RVU 2.60 changed to 3.17
    • Malpractice RVU 0.02 changed to 0.03
    • Practice expense GPCI 0.890 changed to 0.877
    • Malpractice GPCI 0.464 changed to 0.416

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $90.66changed to$102.97

    • Conversion factor 36.0391 changed to 36.0896
    • Practice expense RVU 2.19 changed to 2.60
    • Practice expense GPCI 0.902 changed to 0.890
    • Malpractice GPCI 0.512 changed to 0.464

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $82.77changed to$90.66

    • Conversion factor 35.9996 changed to 36.0391
    • Practice expense RVU 1.95 changed to 2.19

    Held through RVU19B, RVU19C, RVU19D.

  10. January 1, 2018

    RVU18AR1

    $82.69changed to$82.77

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 1.96 changed to 1.95
    • Practice expense GPCI 0.900 changed to 0.902
    • Malpractice GPCI 0.510 changed to 0.512

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    $82.36changed to$82.69

    • Conversion factor 35.8043 changed to 35.8887
    • Practice expense GPCI 0.898 changed to 0.900
    • Malpractice GPCI 0.508 changed to 0.510

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2016

    RVU16A

    $81.55changed to$82.36

    • Conversion factor 35.9335 changed to 35.8043
    • Practice expense RVU 1.92 changed to 1.96
    • Malpractice RVU 0.03 changed to 0.02

    Held through RVU16B, RVU16C, RVU16D.

  13. July 1, 2015

    RVU15C

    $81.14changed to$81.55

    • Conversion factor 35.7547 changed to 35.9335

    Held through RVU15D.

  14. January 1, 2015

    RVU15A

    $78.52changed to$81.14

    • Conversion factor 35.8228 changed to 35.7547
    • Practice expense RVU 1.83 changed to 1.92
    • Malpractice RVU 0.04 changed to 0.03
    • Practice expense GPCI 0.896 changed to 0.898
    • Malpractice GPCI 0.556 changed to 0.508

    Held through RVU15B.

  15. January 1, 2014

    RVU14A

    $79.69changed to$78.52

    • Conversion factor 34.0230 changed to 35.8228
    • Practice expense RVU 2.00 changed to 1.83
    • Practice expense GPCI 0.894 changed to 0.896
    • Malpractice GPCI 0.603 changed to 0.556

    Held through RVU14B, RVU14C, RVU14D.

  16. January 1, 2013

    RVU13AR

    Earliest loaded release: $79.69

    Held through RVU13B, RVU13C, RVU13D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$122.32Not available in this settingRVU26D
2026-07-01$122.32Not available in this settingRVU26C
2026-04-01$122.32Not available in this settingRVU26B
2026-01-01$122.32Not available in this settingRVU26A
2025-10-01$120.39Not available in this settingRVU25D
2025-07-01$120.39Not available in this settingRVU25C
2025-04-01$120.39Not available in this settingRVU25B
2025-01-01$120.39Not available in this settingRVU25A
2024-10-01$125.10Not available in this settingRVU24D
2024-07-01$125.10Not available in this settingRVU24C
2024-04-01$125.10Not available in this settingRVU24B
2024-03-09$125.10Not available in this settingRVU24AR
2024-01-01$123.06Not available in this settingRVU24A
2023-10-01$123.72Not available in this settingRVU23D
2023-07-01$123.72Not available in this settingRVU23C
2023-04-01$123.72Not available in this settingRVU23B
2023-01-01$123.72Not available in this settingRVU23A
2022-10-01$126.51Not available in this settingRVU22D
2022-07-01$126.51Not available in this settingRVU22C
2022-04-01$126.51Not available in this settingRVU22B
2022-01-01$126.51Not available in this settingRVU22A
2021-10-01$115.93Not available in this settingRVU21D
2021-07-01$115.93Not available in this settingRVU21C
2021-04-01$115.93Not available in this settingRVU21B
2021-01-01$115.93Not available in this settingRVU21A
2020-10-01$102.97Not available in this settingRVU20D
2020-07-01$102.97Not available in this settingRVU20C
2020-04-01$102.97Not available in this settingRVU20B
2020-01-01$102.97Not available in this settingRVU20A
2019-10-01$90.66Not available in this settingRVU19D
2019-07-01$90.66Not available in this settingRVU19C
2019-04-01$90.66Not available in this settingRVU19B
2019-01-01$90.66Not available in this settingRVU19A
2018-10-01$82.77Not available in this settingRVU18D
2018-07-01$82.77Not available in this settingRVU18C
2018-04-01$82.77Not available in this settingRVU18B
2018-01-01$82.77Not available in this settingRVU18AR1
2017-10-01$82.69Not available in this settingRVU17D
2017-07-01$82.69Not available in this settingRVU17C
2017-04-01$82.69Not available in this settingRVU17B
2017-01-01$82.69Not available in this settingRVU17A
2016-10-01$82.36Not available in this settingRVU16D
2016-07-01$82.36Not available in this settingRVU16C
2016-04-01$82.36Not available in this settingRVU16B
2016-01-01$82.36Not available in this settingRVU16A
2015-10-01$81.55Not available in this settingRVU15D
2015-07-01$81.55Not available in this settingRVU15C
2015-04-01$81.14Not available in this settingRVU15B
2015-01-01$81.14Not available in this settingRVU15A
2014-10-01$78.52Not available in this settingRVU14D
2014-07-01$78.52Not available in this settingRVU14C
2014-04-01$78.52Not available in this settingRVU14B
2014-01-01$78.52Not available in this settingRVU14A
2013-10-01$79.69Not available in this settingRVU13D
2013-07-01$79.69Not available in this settingRVU13C
2013-04-01$79.69Not available in this settingRVU13B
2013-01-01$79.69Not available in this settingRVU13AR

Price 88319 for an earlier date of service

Where the Idaho rate applies

Idaho is a Medicare payment area, not a city. Our Census mapping connects it to 235 cities and communities in Idaho. Some span more than one payment area; confirm with the service ZIP.

  • Aberdeen
  • Acequia
  • Albion
  • American Falls
  • Ammon
  • Arbon Valley
  • Arco
  • Arimo

Browse all communities in Idaho

88319 billing questions

Is 88319 reported per stain or per specimen?

Report it per specimen analyzed. Multiple enzyme stains on the same specimen do not, by themselves, establish multiple units.

When should 88319 be chosen over 88312 or 88313?

Use 88319 for tissue enzyme histochemistry. Codes 88312 and 88313 cover other special-stain groups, so choose according to the type of stain performed.

How are the professional and technical services reported?

Use modifier 26 for the pathologist’s interpretation and modifier TC for the laboratory work. Without either modifier, the claim represents the global service.

What documentation supports reporting 88319?

The record should identify the tissue specimen and document enzyme histochemical analysis and the resulting interpretation. A general tissue examination alone does not establish this service.

Can 88319 be reported with a surgical pathology examination?

It may be reported with a surgical pathology examination when enzyme histochemistry is separately performed and documented for the specimen. The pathology record should support both services.

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 88319PPRRVU2026_Oct_nonQPP.csv, line 11,227 (RVU26D)
Geographic factors for IdahoGPCI2026.csv, line 47 (RVU26D)

Open CMS sourceHow we calculate rates

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