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

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 Houston, TX, Medicare pays $131.65 for 88319 in the office.

$131.65Office (non-facility)
Not available in this settingHospital or facility
−0.2%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 Houston, TX
  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 Houston, TX 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. Houston, TX pays $131.65. The RVUs are the same everywhere; the geographic indexes change the dollars.

88319 in Houston, TX vs other payment areas
  1. Houston, TX · this page$131.65
  2. Austin, TX · Texas$138.44+$6.79
  3. Beaumont, TX · Texas$121.64−$10.01
  4. Brazoria, TX · Texas$130.83−$0.82
  5. Dallas, TX · Texas$131.49−$0.16
  6. Fort Worth, TX · Texas$130.37−$1.28
  7. Galveston, TX · Texas$131.11−$0.54

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

Every other payment area

88319 in every other Medicare payment locality
Payment localityOfficeFacility
Rest of TexasTexas$126.04—
Los Angeles, CACalifornia$153.09—
Washington, DC areaDistrict of Columbia$153.20—
Miami, FLFlorida$138.12—
Chicago, ILIllinois$133.92—
Manhattan, NYNew York$152.03—
AlaskaAlaska$147.55—
AlabamaAlabama$117.30—

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 Houston, TX 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

102

Locality
Houston, TX
Physician work
1.008
Practice expense
0.993
Malpractice
1.376
Office calculation for 88319 in Houston, TX
ComponentRVULocality factorAdjusted
Physician work0.52× 1.0080.5242
Practice expense3.40× 0.9933.3762
Malpractice0.03× 1.3760.0413
Total RVUs3.9416
Conversion factor× 33.4009

Office rate, Houston, TX$131.65

Office: (0.52 × 1.008 + 3.4 × 0.993 + 0.03 × 1.376) × $33.4009 = $131.65

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 Houston, TX

88319 · Office / nonfacility

$131.65

Effective 2026-10-01

The base rate is $0.65 lower than on 2025-10-01, moving from $132.30 to $131.65 (0.5%).

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

    $132.30changed to$131.65

    • 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
    • Work GPCI 1.014 changed to 1.008
    • Practice expense GPCI 1.003 changed to 0.993
    • Malpractice GPCI 1.409 changed to 1.376

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $137.49changed to$132.30

    • 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

    $135.24changed to$137.49

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $139.36changed to$135.24

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 3.48 changed to 3.54
    • Work GPCI 1.023 changed to 1.014
    • Practice expense GPCI 1.016 changed to 1.003
    • Malpractice GPCI 1.154 changed to 1.409
  5. January 1, 2023

    RVU23A

    $146.28changed to$139.36

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 3.55 changed to 3.48
    • Work GPCI 1.032 changed to 1.023
    • Practice expense GPCI 1.029 changed to 1.016
    • Malpractice GPCI 0.900 changed to 1.154

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $133.85changed to$146.28

    • 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

    $116.00changed to$133.85

    • 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
    • Work GPCI 1.026 changed to 1.032
    • Practice expense GPCI 1.020 changed to 1.029
    • Malpractice GPCI 0.918 changed to 0.900

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $100.03changed to$116.00

    • Conversion factor 36.0391 changed to 36.0896
    • Practice expense RVU 2.19 changed to 2.60
    • Work GPCI 1.020 changed to 1.026
    • Practice expense GPCI 1.012 changed to 1.020
    • Malpractice GPCI 0.936 changed to 0.918

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $91.18changed to$100.03

    • 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

    $91.06changed to$91.18

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 1.96 changed to 1.95
    • Practice expense GPCI 1.009 changed to 1.012
    • Malpractice GPCI 0.946 changed to 0.936

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    $90.62changed to$91.06

    • Conversion factor 35.8043 changed to 35.8887
    • Work GPCI 1.019 changed to 1.020
    • Practice expense GPCI 1.006 changed to 1.009
    • Malpractice GPCI 0.955 changed to 0.946

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2016

    RVU16A

    $89.84changed to$90.62

    • 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

    $89.40changed to$89.84

    • Conversion factor 35.7547 changed to 35.9335

    Held through RVU15D.

  14. January 1, 2015

    RVU15A

    $86.42changed to$89.40

    • 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
    • Work GPCI 1.014 changed to 1.019
    • Practice expense GPCI 1.004 changed to 1.006
    • Malpractice GPCI 0.939 changed to 0.955

    Held through RVU15B.

  15. January 1, 2014

    RVU14A

    $87.63changed to$86.42

    • Conversion factor 34.0230 changed to 35.8228
    • Practice expense RVU 2.00 changed to 1.83
    • Work GPCI 1.009 changed to 1.014
    • Practice expense GPCI 1.002 changed to 1.004
    • Malpractice GPCI 0.923 changed to 0.939

    Held through RVU14B, RVU14C, RVU14D.

  16. January 1, 2013

    RVU13AR

    Earliest loaded release: $87.63

    Held through RVU13B, RVU13C, RVU13D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$131.65Not available in this settingRVU26D
2026-07-01$131.65Not available in this settingRVU26C
2026-04-01$131.65Not available in this settingRVU26B
2026-01-01$131.65Not available in this settingRVU26A
2025-10-01$132.30Not available in this settingRVU25D
2025-07-01$132.30Not available in this settingRVU25C
2025-04-01$132.30Not available in this settingRVU25B
2025-01-01$132.30Not available in this settingRVU25A
2024-10-01$137.49Not available in this settingRVU24D
2024-07-01$137.49Not available in this settingRVU24C
2024-04-01$137.49Not available in this settingRVU24B
2024-03-09$137.49Not available in this settingRVU24AR
2024-01-01$135.24Not available in this settingRVU24A
2023-10-01$139.36Not available in this settingRVU23D
2023-07-01$139.36Not available in this settingRVU23C
2023-04-01$139.36Not available in this settingRVU23B
2023-01-01$139.36Not available in this settingRVU23A
2022-10-01$146.28Not available in this settingRVU22D
2022-07-01$146.28Not available in this settingRVU22C
2022-04-01$146.28Not available in this settingRVU22B
2022-01-01$146.28Not available in this settingRVU22A
2021-10-01$133.85Not available in this settingRVU21D
2021-07-01$133.85Not available in this settingRVU21C
2021-04-01$133.85Not available in this settingRVU21B
2021-01-01$133.85Not available in this settingRVU21A
2020-10-01$116.00Not available in this settingRVU20D
2020-07-01$116.00Not available in this settingRVU20C
2020-04-01$116.00Not available in this settingRVU20B
2020-01-01$116.00Not available in this settingRVU20A
2019-10-01$100.03Not available in this settingRVU19D
2019-07-01$100.03Not available in this settingRVU19C
2019-04-01$100.03Not available in this settingRVU19B
2019-01-01$100.03Not available in this settingRVU19A
2018-10-01$91.18Not available in this settingRVU18D
2018-07-01$91.18Not available in this settingRVU18C
2018-04-01$91.18Not available in this settingRVU18B
2018-01-01$91.18Not available in this settingRVU18AR1
2017-10-01$91.06Not available in this settingRVU17D
2017-07-01$91.06Not available in this settingRVU17C
2017-04-01$91.06Not available in this settingRVU17B
2017-01-01$91.06Not available in this settingRVU17A
2016-10-01$90.62Not available in this settingRVU16D
2016-07-01$90.62Not available in this settingRVU16C
2016-04-01$90.62Not available in this settingRVU16B
2016-01-01$90.62Not available in this settingRVU16A
2015-10-01$89.84Not available in this settingRVU15D
2015-07-01$89.84Not available in this settingRVU15C
2015-04-01$89.40Not available in this settingRVU15B
2015-01-01$89.40Not available in this settingRVU15A
2014-10-01$86.42Not available in this settingRVU14D
2014-07-01$86.42Not available in this settingRVU14C
2014-04-01$86.42Not available in this settingRVU14B
2014-01-01$86.42Not available in this settingRVU14A
2013-10-01$87.63Not available in this settingRVU13D
2013-07-01$87.63Not available in this settingRVU13C
2013-04-01$87.63Not available in this settingRVU13B
2013-01-01$87.63Not available in this settingRVU13AR

Price 88319 for an earlier date of service

Where the Houston, TX rate applies

Houston, TX is a Medicare payment area, not a city. Our Census mapping connects it to 46 cities and communities in Texas. Some span more than one payment area; confirm with the service ZIP.

Browse all communities in Texas

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 Houston, TXGPCI2026.csv, line 102 (RVU26D)

Open CMS sourceHow we calculate rates

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