CPT code 94727: Lung volumes, gas dilution or washout2026 Medicare rate & RVUs in Missouri
Measures lung volumes using gas dilution or washout, typically in a pulmonary function laboratory when a clinician needs lung-volume data.
Medicare pays $44.13–$47.81 for 94727 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 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 in Missouri
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
3 payment localities
$44.13 to $47.81
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Kansas City, MO | $47.27 | Unavailable |
| Metropolitan St. Louis, MO | $47.81 | Unavailable |
| Rest of Missouri | $44.13 | Unavailable |
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.
How the rate is built · 94727
RVUs × geographic indexes × conversion factor
Work0.25
0.25 RVUs× 1.000 GPCI
Practice expense1.22
1.22 RVUs× 1.000 GPCI
Malpractice0.02
0.02 RVUs× 1.000 GPCI
Adjusted RVUs
1.4900
Conversion factor
$33.4009
Medicare rate
$49.77
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 94727
The CMS indicators that decide how 94727 is paid alongside other services.
CMS payment indicators · 94727
Lung volumes, gas dilution or washout
| 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
94727 without 26 · national office
$49.77
Lung volumes, gas dilution or washout
94727-26 · Professional component
$12.02
Pays only the interpretation and report.
94727 compared with similar codes
Compare codes · National
4 codes, side by side
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.
94727 billing questions
How does 94727 differ from 94726?
Code 94727 is for lung volumes measured by gas dilution or washout. Use 94726 for the plethysmographic method.
Can 94727 be reported with a diffusion-capacity test?
Yes. A gas-dilution lung-volume test and a diffusion-capacity test measure different pulmonary functions and may be performed during the same testing encounter.
Which modifiers identify the components?
Modifier 26 identifies the professional interpretation, and modifier TC identifies the technical service, including equipment and staff. Without either modifier, the claim represents the global service.
Should each measured lung volume be reported as a separate unit?
No. Report the gas-dilution or washout test service, not separate units for functional residual capacity, residual volume, and total lung capacity.
What documentation supports 94727?
Document the gas-dilution or washout method, the resulting lung-volume measurements, and the clinician’s interpretation. The method helps distinguish this service from plethysmography.
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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