CPT code 94690: Metabolic testing, resting oxygen uptake2026 Medicare rate & RVUs in Massachusetts
Measures oxygen uptake at rest by indirect calorimetry to estimate resting energy expenditure when a patient’s nutritional needs require metabolic assessment.
Medicare pays $54.96–$62.05 for 94690 in the office in Massachusetts, from Rest of Massachusetts to Metropolitan Boston, MA. 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.
Your location
On this page 9 sections
What 94690 covers
This test measures oxygen uptake while the patient is resting, using indirect calorimetry to estimate resting energy expenditure. It is used when a clinical team needs an individualized measure to support nutritional management, such as for a patient with complex energy needs. Testing is typically performed in a pulmonary or metabolic testing setting by trained staff using gas-analysis equipment, with a clinician interpreting the results.
Report 94690 for the resting indirect-calorimetry service, not for exercise testing or a broader expired-gas analysis. Documentation should identify the clinical reason for measuring resting energy expenditure, confirm that the measurement was obtained at rest, and include the test findings and interpretation. CMS recognizes a global service when billed without a component modifier, or separate professional and technical portions: modifier 26 represents interpretation, while modifier TC represents the equipment and staff portion. Both modifiers are separately priced.
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 94690 pays more and less in Massachusetts
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Boston, MA | $62.05 | Unavailable |
| Rest of Massachusetts | $54.96 | Unavailable |
How the 94690 rate is calculated
Each of 94690’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 · 94690
RVUs × geographic indexes × conversion factor
Work0.07
0.07 RVUs× 1.000 GPCI
Practice expense1.48
1.48 RVUs× 1.000 GPCI
Malpractice0.02
0.02 RVUs× 1.000 GPCI
Adjusted RVUs
1.5700
Conversion factor
$33.4009
Medicare rate
$52.44
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 94690
The CMS indicators that decide how 94690 is paid alongside other services.
CMS payment indicators · 94690
Metabolic testing, resting oxygen uptake
| 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
94690 without 26 · national office
$52.44
Metabolic testing, resting oxygen uptake
94690-26 · Professional component
$3.67
Pays only the interpretation and report.
94690 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 94680Oxygen uptake testDirect, rest and exercise
- 94690 is limited to oxygen uptake measured at rest by indirect calorimetry. 94680 is for expired-gas analysis that includes additional gas-exchange measurements.
- 94681Gas-exchange analysisCO2 output and derived measures
- 94690 reports resting indirect calorimetry. 94681 is expired-gas analysis that includes calculation of the respiratory quotient.
- 94621Exercise testCardiopulmonary gas analysis
- 94690 measures oxygen uptake at rest. 94621 is used for cardiopulmonary exercise testing, which evaluates the patient during exertion.
94690 billing questions
When should 94690 be chosen instead of 94680?
Use 94690 for oxygen uptake measured at rest by indirect calorimetry. Code 94680 describes expired-gas analysis with a broader set of measurements.
How does 94690 differ from 94681?
94690 is specifically for resting oxygen uptake by indirect calorimetry. Code 94681 includes expired-gas analysis with calculation of the respiratory quotient.
Can the professional and technical portions be billed separately?
Yes. Modifier 26 identifies the interpretation, and modifier TC identifies the equipment and staff portion. Billing without either modifier represents the global service.
What documentation supports reporting 94690?
Document the clinical reason for measuring resting energy expenditure, that the patient was tested at rest, the measured findings, and the interpretation.
Is this code for a pulmonary exercise test?
No. 94690 reports resting oxygen uptake by indirect calorimetry; exercise-based pulmonary or cardiopulmonary testing is reported with a different code.
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
Show the CMS file lines behind this rate
Fee sheets · Coming soon
Put 94690 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Join the waitlist