CPT code 94727: Lung volumes, gas dilution or washout2026 Medicare rate & RVUs

Medicare pays $49.77 for 94727 nationally in the office. Local office rates run $43.70–$68.39.

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

What 94727 covers

Code 94727 covers lung-volume measurement by gas dilution or washout, commonly using helium dilution or nitrogen washout in a pulmonary function laboratory. The test estimates functional residual capacity and derives residual volume and total lung capacity; respiratory therapists typically conduct the maneuver, with a clinician interpreting the results. Because the method measures gas that reaches communicating airways, its lung-volume results can differ from body plethysmography when air trapping is present.

Select 94727 when the documented method is gas dilution or washout, rather than the plethysmographic method reported with 94726. The record should identify the testing method, include the resulting lung-volume measurements, and support the interpreting clinician’s conclusions. CMS recognizes separately priced professional and technical components: use modifier 26 for interpretation, modifier TC for equipment and staff, or report without either modifier for the global service. Report the test service rather than separate units for each calculated volume.

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 94727 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

94727 rates by state

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

How the 94727 rate is calculated

Each of 94727’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 94727

The CMS indicators that decide how 94727 is paid alongside other services.

What modifiers do to the payment

When to use modifier 26

94727 compared with similar codes

How to choose

94726Body plethysmographyLung volumes, plethysmographic method

Choose 94727 for lung-volume measurement by gas dilution or washout; choose 94726 when the documented method is plethysmography.

94729Diffusing capacity (DLCO)Add-on to pulmonary function testing

Code 94729 measures pulmonary diffusing capacity, not lung volumes. It may be performed in the same testing encounter as 94727.

94728Airway resistanceOscillometry

Code 94728 measures airway resistance using oscillometry. Code 94727 measures lung volumes using gas dilution or washout.

Codes related to 94727

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