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Billing code 94681: Gas-exchange analysisMedicare rate & RVUs

Reports expired-gas analysis measuring oxygen uptake, carbon dioxide output, oxygen extraction, and derived values at rest or during exercise.

CMS RVU26DEffective Oct 1, 2026109 payment localities3K Medicare services in 2024

Medicare pays $50.10 for 94681 nationally in the office. Local office rates run $43.63–$69.12.

Medicare rate · 94681

Gas-exchange analysis

Work RVUs
0.2
Total RVUs
1.50
Global days
XXX

National rate · 2026

$50.10

Office setting, before claim adjustments.

See every locality for 94681 →Billed by an NP, PA or therapist? →

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

On this page 10 sections
  1. Medicare rate
  2. What 94681 covers
  3. By payment locality
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Similar codes
  8. Related codes
  9. Billing questions
  10. Sources

What 94681 covers

This test analyzes expired gas to quantify oxygen uptake, carbon dioxide output, oxygen extraction percentage, and related derived values. It may be performed at rest or with exercise, often in a pulmonary function or exercise physiology laboratory when a clinician needs detailed metabolic gas-exchange data. Pulmonary laboratory staff, such as respiratory therapists, typically operate the analyzer, with a qualified professional interpreting the results.

Select 94681 when the performed analysis includes carbon dioxide output, oxygen extraction, and other derived gas-exchange measures; document the test conditions, whether exercise was used, the measurements, and the interpretation. Distinguish it from simpler oxygen-uptake analysis and indirect resting measurement. CMS recognizes professional and technical components: report modifier 26 for interpretation, TC for equipment and staff, or neither modifier for the global service.

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 94681 pays more and less

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

109 payment localities

$43.63 to $69.12

$43.63$56.38$69.12
One dot per payment locality, office / nonfacility. Hover a dot to see the locality; select it to open that rate.

109 of 109 payment localities

94681 office and facility rates by payment locality
Payment localityOfficeFacility
Alabama$44.36Unavailable
Alaska*$55.75Unavailable
Arizona$48.64Unavailable
Arkansas$43.63Unavailable
Atlanta$51.00Unavailable
Austin$52.46Unavailable
Bakersfield$53.91Unavailable
Baltimore/Surr. Cntys$53.54Unavailable
Beaumont$46.21Unavailable
Brazoria$49.55Unavailable

94681 rates by state

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

MEWIVTNHMTNDMNMINYMARIWAIDWYSDIAILINOHPANJCTORNVUTCONEMOKYWVVAMDDECAAZNMKSOKARTNNCSCDCTXLAMSALGAFLAKHI

Explore a state

Local rates. Clear comparisons.

Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.

$43.63

$61.47

Color shows the midpoint of each state’s locality range.

View every state and territory as a table
94681 office rate range by state
State / territoryOffice rate rangeLocalities
AK$55.751
AL$44.361
AR$43.631
AZ$48.641
CA$53.82–$69.1229
CO$52.681
CT$53.711
DC$58.131
DE$49.521
FL$48.74–$53.373
GA$45.71–$51.002
GU$55.491
HI$55.491
IA$45.891
ID$46.181
IL$46.98–$52.074
IN$46.491
KS$45.531
KY$45.311
LA$45.18–$47.732
MA$52.25–$58.492
MD$50.60–$58.133
ME$46.33–$49.352
MI$46.54–$49.302
MN$50.631
MO$44.22–$48.073
MS$43.941
MT$50.101
NC$46.901
ND$49.511
NE$46.211
NH$51.721
NJ$54.37–$57.382
NM$46.781
NV$49.981
NY$47.68–$59.405
OH$46.421
OK$45.341
OR$49.63–$54.662
PA$46.57–$52.152
PR$50.551
RI$51.521
SC$46.731
SD$49.441
TN$45.781
TX$46.21–$52.468
UT$47.451
VA$49.09–$58.132
VI$50.551
VT$49.181
WA$52.20–$59.882
WI$47.631
WV$44.981
WY$49.841

How the 94681 rate is calculated

Each of 94681’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 · 94681

RVUs × geographic indexes × conversion factor

Work0.20

0.20 RVUs× 1.000 GPCI

Practice expense1.27

1.27 RVUs× 1.000 GPCI

Malpractice0.03

0.03 RVUs× 1.000 GPCI

Adjusted RVUs

1.5000

Conversion factor

$33.4009

Medicare rate

$50.10

Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.

Payment rules and modifiers for 94681

The CMS indicators that decide how 94681 is paid alongside other services.

CMS payment indicators · 94681

Gas-exchange analysis

RuleCMS valueWhat it means
Global periodXXXThe global surgery concept doesn’t apply.
Multiple procedures0No multiple-procedure reduction.
Bilateral (modifier 50)0The 150% bilateral adjustment doesn’t apply.
Assistant at surgery (80/81/82/AS)0Not paid without supporting documentation.
Co-surgeons (62)0Not permitted.
Team surgery (66)0Not permitted.
Professional/technical1Diagnostic test with separate professional (26) and technical (TC) components.

What modifiers do to the payment

Modifier 26 · payment effect

With and without the modifier

94681 without 26 · national office

$50.10

Gas-exchange analysis

94681-26 · Professional component

$9.69

Pays only the interpretation and report.

When to use modifier 26

94681 compared with similar codes

Compare codes · National

4 codes, side by side

  • 94681

    Gas-exchange analysis0.2 wRVU

    $50.10

  • 94680

    Oxygen uptake test0.25 wRVU

    $57.78+$7.68

  • 94690

    Metabolic testing0.07 wRVU

    $52.44+$2.34

  • 94621

    Exercise test1.38 wRVU

    $165.67+$115.57

How to choose

94680Oxygen uptake test
94680 represents simpler oxygen-uptake analysis. 94681 includes carbon dioxide output, oxygen extraction, and related derived measures.
94690Metabolic testing
94690 is an indirect oxygen-uptake measurement at rest. 94681 analyzes a broader set of expired-gas measures and may be performed with or without exercise.
94621Exercise test
94621 is a broader cardiopulmonary exercise test with electrocardiographic recording. Use 94681 for the expired-gas analysis when that full exercise-testing service is not performed.

Codes related to 94681

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

Codes related to 94681
CodeHow it relatesNational office range
Same family
94680Oxygen uptake testA simpler oxygen-uptake analysis, without 94681's broader gas-exchange measures.$50.47–$79.64
Used instead
94690Metabolic testingFor indirect oxygen-uptake measurement at rest rather than 94681's broader analysis.$45.15–$74.24
94621Exercise testFor cardiopulmonary exercise testing that includes electrocardiographic recording.$147.77–$220.87

94681 billing questions

How does 94681 differ from 94680?

94681 captures carbon dioxide output, oxygen extraction, and additional derived gas-exchange values. Use 94680 for the simpler oxygen-uptake analysis described by that code.

Can 94681 be performed without exercise?

Yes. The analysis may be performed at rest or with exercise; document the conditions under which the gas measurements were obtained.

Which modifiers identify the professional and technical components?

Append modifier 26 for the interpretation and TC for the equipment and staff portion. Without either modifier, the claim represents the global service.

Are oxygen uptake and the derived gas measurements separate units?

No. Report the analysis as one service rather than separate units for each gas measurement or derived value.

When would 94621 be a better fit?

94621 describes cardiopulmonary exercise testing with electrocardiographic recording and gas-exchange measurements. Choose it when that broader exercise test is performed rather than an expired-gas analysis alone.

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
RVUs for 94681PPRRVU2026_Oct_nonQPP.csv, line 12,424 (RVU26D)

Open CMS sourceHow we calculate rates

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