CPT code 78598: Lung V/Q imaging, differential ventilation and perfusion2026 Medicare rate & RVUs in Missouri
Reports a nuclear medicine study measuring the relative ventilation and perfusion of lung regions, often for preoperative assessment of remaining lung function.
Medicare pays $232.48–$253.64 for 78598 in the office in Missouri, from Rest of Missouri to Metropolitan St. Louis, MO. Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
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What 78598 covers
This nuclear medicine examination images both airflow and blood flow in the lungs and measures their relative distribution between lung regions. A patient being evaluated for lung resection may undergo the study to help estimate how much functioning lung would remain. Imaging staff administer and acquire the ventilation and perfusion portions; a radiologist or nuclear medicine physician interprets the images and differential results. The examination may be performed in a hospital department or imaging center.
Select 78598 when the completed study includes both ventilation and perfusion imaging with differential measurements. The report should identify the two portions of the examination and document the regional results, rather than describe only a standard combined scan. For Medicare physician fee schedule billing, modifier 26 identifies the physician’s interpretation, and modifier TC identifies the equipment-and-staff portion. A claim without either modifier represents the global service, combining both components. A completed dual-portion differential examination is reported with this combined code rather than separate single-portion imaging codes.
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 78598 pays more and less in Missouri
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
3 payment localities
$232.48 to $253.64
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Kansas City, MO | $250.52 | Unavailable |
| Metropolitan St. Louis, MO | $253.64 | Unavailable |
| Rest of Missouri | $232.48 | Unavailable |
How the 78598 rate is calculated
Each of 78598’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 · 78598
RVUs × geographic indexes × conversion factor
Work0.83
0.83 RVUs× 1.000 GPCI
Practice expense7.01
7.01 RVUs× 1.000 GPCI
Malpractice0.09
0.09 RVUs× 1.000 GPCI
Adjusted RVUs
7.9300
Conversion factor
$33.4009
Medicare rate
$264.87
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 78598
The CMS indicators that decide how 78598 is paid alongside other services.
CMS payment indicators · 78598
Lung V/Q imaging, differential ventilation and perfusion
| Rule | CMS value | What it means |
|---|---|---|
| Global period | XXX | The global surgery concept doesn’t apply. |
| Multiple procedures | 0 | No multiple-procedure reduction. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 1 | Diagnostic test with separate professional (26) and technical (TC) components. |
What modifiers do to the payment
Modifier 26 · payment effect
With and without the modifier
78598 without 26 · national office
$264.87
Lung V/Q imaging, differential ventilation and perfusion
78598-26 · Professional component
$37.74
Pays only the interpretation and report.
78598 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 78582Lung scanVentilation and perfusion
- Choose 78582 for a combined ventilation-perfusion examination without differential measurements. Choose 78598 when the completed examination measures the regional distribution of both.
- 78597Lung perfusionDifferential quantification
- 78597 measures differential perfusion. 78598 requires the combined differential ventilation and perfusion examination.
- 78580Lung perfusion scanPerfusion only
- 78580 covers perfusion imaging alone. It does not represent an examination that also measures differential ventilation.
78598 billing questions
How is 78598 different from 78582?
Both involve ventilation and perfusion imaging. Use 78598 when the examination also measures their differential distribution between lung regions; 78582 describes the combined imaging without that differential measurement.
When would 78597 be reported instead?
78597 is for differential perfusion imaging. Choose 78598 when differential ventilation is measured along with differential perfusion.
Should ventilation and perfusion be reported as two single-portion codes?
For one completed examination that measures both portions differentially, report the combined service with 78598 rather than splitting it into ventilation-only and perfusion-only codes.
Which component does modifier 26 identify?
Modifier 26 identifies the physician’s interpretation and report of the differential ventilation and perfusion study. Modifier TC identifies the equipment-and-staff portion; billing without either modifier represents both components.
What should the report show to support 78598?
It should document that both ventilation and perfusion imaging were performed and include the differential regional findings. A report describing only perfusion measurements does not establish the combined differential service.
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.
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