Billing code 78191: Platelet studyMedicare rate & RVUs in Guam

Reports a study that measures platelet survival over time to investigate shortened platelet lifespan or suspected platelet destruction and sequestration.

CMS RVU26DEffective Oct 1, 20261 payment locality

Medicare pays $140.31 for 78191 in the office in Guam (Hawaii, Guam). Which amount applies depends on the service address.

$140.31Office (non-facility)
—Hospital or facility

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 78191 for the payment locality that covers the ZIP.

On this page 9 sections
  1. Rate in Guam
  2. What 78191 covers
  3. By payment locality
  4. How it’s calculated
  5. Payment rules
  6. Similar codes
  7. Related codes
  8. Billing questions
  9. Sources

What 78191 covers

This diagnostic study evaluates how long platelets remain in circulation and may help investigate thrombocytopenia when shortened survival or sequestration is suspected. It involves studying the patient’s platelets over time; nuclear medicine and laboratory personnel may perform the technical work, while a physician interprets the findings. The study is distinct from imaging the spleen alone and from tests that track red blood cells.

Report 78191 for the platelet-survival study as a whole, supported by the order, records of the study performed, and the physician’s interpretation. CMS recognizes a professional component for interpretation and a technical component for equipment and staff. Bill the professional work with modifier 26, the technical work with modifier TC, or the global service without either modifier when one entity provides both components. The documentation should identify the clinical question and support the component billed.

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.

78191 in Hawaii, Guam

78191 office and facility rates by payment locality
Payment localityOfficeFacility
Hawaii, Guam$140.31Unavailable

How the 78191 rate is calculated

Each of 78191’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 · 78191

RVUs × geographic indexes × conversion factor

Swap in your local Medicare rate.

Work 0.59Practice expense 3.14Malpractice 0.07

3.8000 adjusted RVUs×$33.4009 conversion factor=$126.92

All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.

Payment rules and modifiers for 78191

The CMS indicators that decide how 78191 is paid alongside other services.

CMS payment indicators · 78191

Platelet study

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

78191 without 26 · national office

$126.92

Platelet study

78191-26 · Professional component

$23.71

Pays only the interpretation and report.

When to use modifier 26

78191 compared with similar codes

Compare codes

78191 vs 78130 vs 78140 vs 78185: national Medicare rates

Swap in your local Medicare rate.

  • 78191
    Platelet study · 0.59 wRVU
    $126.92
  • 78130
    Red-cell survival · 0.59 wRVU
    $126.92+$0.00
  • 78140
    Red-cell study · 0.59 wRVU
    $109.89−$17.03
  • 78185
    Spleen imaging · 0.39 wRVU
    $154.31+$27.39

How to choose

78130Red-cell survival
Choose 78191 for platelet survival and 78130 for red-cell survival; the tracked blood-cell type distinguishes the studies.
78140Red-cell study
78191 evaluates platelet survival, while 78140 evaluates red-cell sequestration.
78185Spleen imaging
78191 studies platelet survival over time. 78185 reports spleen imaging, not platelet-survival measurement.

78191 billing questions

How is 78191 different from a red-cell survival study?

78191 evaluates platelet survival. Use 78130 when the study tracks red-cell survival instead.

When should modifier 26 or TC be reported?

Use modifier 26 for the physician’s interpretation and modifier TC for the technical component. Report the global service without either modifier when both components are billed together.

What documentation supports the professional component?

The record should include the clinical question and the physician’s interpretation of the platelet-survival findings.

Does the technical component include the interpretation?

No. CMS identifies equipment and staff as the technical component; physician interpretation is the professional component.

Is this the code for spleen imaging?

No. 78191 evaluates platelet survival. 78185 is the spleen-imaging code when the service performed is imaging the spleen.

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 78191PPRRVU2026_Oct_nonQPP.csv, line 9,248 (RVU26D)
Geographic factors for Hawaii, GuamGPCI2026.csv, line 46 (RVU26D)

Open CMS sourceHow we calculate rates

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