CPT code 88373: ISH analysis, computer-assisted morphometry2026 Medicare rate & RVUs

Computer-assisted morphometric analysis quantifies or semi-quantifies in situ hybridization findings, such as signal patterns evaluated in tumor tissue.

CMS RVU26DEffective Oct 1, 2026109 payment localities6.5K Medicare services in 2024

Medicare pays $63.46 for 88373 nationally in the office. Local office rates run $57.08–$84.89.

Medicare rate · 88373

ISH analysis, computer-assisted morphometry

Office or facility?

Work RVUs
0.57
Total RVUs
1.90
Global days
ZZZ

National rate · 2026

$63.46

Office setting, before claim adjustments.

See every locality for 88373 →Billed by an NP, PA or therapist? →

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

Your location

Medicare pays by the payment locality where the service is performed.

On this page 10 sections
  1. Medicare rate
  2. What 88373 covers
  3. By payment locality
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Similar codes
  8. Related codes
  9. Billing questions
  10. Sources

What 88373 covers

This service uses computer-assisted image analysis to quantify or semi-quantify findings from in situ hybridization (ISH) in a tissue specimen. A pathologist or qualified laboratory professional typically evaluates stained slides with imaging equipment and analysis software. A familiar clinical setting is assessment of HER2-related signals in breast carcinoma tissue; the method applies when the requested ISH findings require morphometric measurement rather than a qualitative read alone.

Select the service based on the computer-assisted morphometric method and the documented assay and specimen. The record should identify the tissue examined, probe or assay, analysis method, measured findings, and resulting interpretation. CMS treats 88373 as an add-on code: report it only with a primary procedure, and payment falls within that procedure’s global period. The service has separately priced professional and technical components: modifier 26 identifies interpretation, modifier TC identifies equipment and staff, and no component 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.

Where 88373 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 payment localities

$57.08 to $84.89

$57.08$70.98$84.89
One dot per payment locality, office / nonfacility. Hover a dot to see the locality; select it to open that rate.

109 of 109 payment localities

88373 office and facility rates by payment locality
Payment localityOfficeFacility
Alabama$57.81Unavailable
Alaska$75.70Unavailable
Arizona$62.05Unavailable
Arkansas$57.08Unavailable
Atlanta, GA$64.29Unavailable
Austin, TX$66.02Unavailable
Bakersfield, CA$67.93Unavailable
Baltimore area, MD$67.06Unavailable
Beaumont, TX$59.47Unavailable
Brazoria, TX$63.14Unavailable

88373 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.

$57.08

$76.38

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

View every state and territory as a table
88373 office rate range by state
State / territoryOffice rate rangeLocalities
AK$75.701
AL$57.811
AR$57.081
AZ$62.051
CA$67.86–$84.8929
CO$66.441
CT$67.311
DC$72.381
DE$62.991
FL$61.69–$65.783
GA$58.76–$64.292
GU$69.361
HI$69.361
IA$59.511
ID$59.761
IL$59.81–$65.044
IN$60.071
KS$59.061
KY$58.541
LA$58.38–$60.912
MA$66.04–$72.762
MD$64.15–$72.383
ME$59.81–$62.942
MI$59.67–$62.152
MN$64.511
MO$57.37–$61.353
MS$57.251
MT$63.461
NC$60.391
ND$63.261
NE$59.861
NH$65.231
NJ$68.31–$71.742
NM$59.871
NV$63.451
NY$61.16–$73.305
OH$59.631
OK$58.671
OR$63.19–$68.572
PA$59.83–$65.682
PR$63.941
RI$65.241
SC$60.061
SD$63.241
TN$59.291
TX$59.47–$66.028
UT$60.781
VA$62.61–$72.382
VI$63.941
VT$62.861
WA$65.97–$74.362
WI$61.381
WV$57.831
WY$63.371

How the 88373 rate is calculated

Each of 88373’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 · 88373

RVUs × geographic indexes × conversion factor

Office or facility?

Work0.57

0.57 RVUs× 1.000 GPCI

Practice expense1.32

1.32 RVUs× 1.000 GPCI

Malpractice0.01

0.01 RVUs× 1.000 GPCI

Adjusted RVUs

1.9000

Conversion factor

$33.4009

Medicare rate

$63.46

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

Payment rules and modifiers for 88373

The CMS indicators that decide how 88373 is paid alongside other services.

CMS payment indicators · 88373

ISH analysis, computer-assisted morphometry

RuleCMS valueWhat it means
Global periodZZZAdd-on code: falls within the primary procedure’s global period.
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

88373 without 26 · national office

$63.46

ISH analysis, computer-assisted morphometry

88373-26 · Professional component

$23.71

Pays only the interpretation and report.

When to use modifier 26

88373 compared with similar codes

Compare codes · National

4 codes, side by side

Office or facility?

  • 88373

    ISH analysis, computer-assisted morphometry0.57 wRVU

    $63.46

  • 88369

    ISH morphometry, quantitative or semiquantitative0.68 wRVU

    $128.93+$65.47

  • 88367

    ISH analysis, automated morphometric analysis0.71 wRVU

    $104.88+$41.42

  • 88361

    Tumor immunohistochemistry, computer-assisted analysis0.93 wRVU

    $114.57+$51.11

How to choose

88369ISH morphometryQuantitative or semiquantitative
Choose 88373 for computer-assisted morphometric ISH analysis; 88369 represents manual morphometric analysis.
88367ISH analysisAutomated morphometric analysis
88367 represents automated ISH. 88373 is distinguished by quantitative or semi-quantitative morphometric analysis using computer-assisted technology.
88361Tumor immunohistochemistryComputer-assisted analysis
88361 is computer-assisted tumor immunohistochemistry analysis. 88373 concerns morphometric analysis of ISH findings, a different assay.

88373 billing questions

How does 88373 differ from 88369?

88373 is for computer-assisted morphometric analysis of ISH findings. Use 88369 when the morphometric analysis is performed manually.

Can 88373 be reported by itself?

No. CMS identifies it as an add-on code, so it must be reported with a primary procedure. Payment is within that primary procedure’s global period.

When should modifier 26 or TC be used?

Use modifier 26 for the professional interpretation and modifier TC for the technical service, including equipment and staff. Report the global service without either component modifier.

What documentation supports 88373?

Document the specimen, ISH assay or probe, use of computer-assisted morphometric analysis, measured findings, and interpretation. The record should make clear that the work was quantitative or semi-quantitative.

Is this the same as automated ISH?

Not necessarily. 88373 describes computer-assisted morphometric measurement; an ISH service without that morphometric analysis may be represented by a different 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 88373PPRRVU2026_Oct_nonQPP.csv, line 11,307 (RVU26D)

Open CMS sourceHow we calculate rates

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