CPT code 78598: Lung V/Q imaging, differential ventilation and perfusion2026 Medicare rate & RVUs

Medicare pays $264.87 for 78598 nationally in the office. Local office rates run $230.40–$370.01.

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

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

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

109 of 109 payment localities

78598 rates by state

Office rate range in each state. Select a state to see its payment localities.

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.

Payment rules and modifiers for 78598

The CMS indicators that decide how 78598 is paid alongside other services.

What modifiers do to the payment

When to use modifier 26

78598 compared with similar codes

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.

Codes related to 78598

Related codes aren’t interchangeable: bill the code that matches the service performed.

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

Open CMS sourceHow we calculate rates