CPT code 94726: Body plethysmography, lung volumes, plethysmographic method2026 Medicare rate & RVUs in California

Medicare pays $68.70–$88.31 for 94726 in the office in California, from Chico, CA to San Benito County, CA. 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.

What 94726 covers

During body plethysmography, the patient sits in a sealed body box and pants against a temporarily closed mouthpiece shutter. Pressure changes establish thoracic gas volume; the laboratory combines this measurement with spirometric values to derive functional residual capacity, residual volume, and total lung capacity. Airway resistance and conductance measured as part of plethysmography are included. Respiratory therapists or pulmonary function technologists perform the study in office or hospital pulmonary function laboratories, and a pulmonologist typically interprets it. Clinicians order it to investigate suspected restriction after a low vital capacity or to assess hyperinflation and air trapping in COPD or asthma.

Report one unit for a plethysmographic lung volume study; use 94727 instead when volumes are measured by gas dilution or washout. Document the method, quality of the maneuvers, measured volumes, and interpretation. CMS recognizes a professional component for physician interpretation (modifier 26) and a technical component for equipment and staff (modifier TC); an entity furnishing both bills the global service without a modifier. For a hospital outpatient test, the physician reports the interpretation with modifier 26, while the hospital bills its facility service. Diffusing capacity, when performed, is separately reported with add-on code 94729.

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 94726 pays more and less in California

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

29 of 29 payment localities

How the 94726 rate is calculated

Each of 94726’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 94726

The CMS indicators that decide how 94726 is paid alongside other services.

What modifiers do to the payment

When to use modifier 26

94726 compared with similar codes

How to choose

94727Lung volumesGas dilution or washout

94727 measures lung volumes by inert gas dilution or nitrogen washout. 94726 uses a sealed body plethysmograph. Report one method for the session.

94728Airway resistanceOscillometry

94728 measures airway resistance by oscillometry without a body box. Resistance measured as part of plethysmography is included in 94726.

94010SpirometryNo post-bronchodilator comparison

94010 measures airflow and vital capacity by spirometry but cannot measure residual volume or total lung capacity. Those measurements require lung volume testing, such as 94726 or 94727.

Codes related to 94726

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