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Billing code 94450: Hypoxia response testMedicare rate & RVUs

Reports testing of a patient's breathing response during controlled hypoxia, typically in a pulmonary function laboratory when ventilatory response is being evaluated.

CMS RVU26DEffective Oct 1, 2026109 payment localities771 Medicare services in 2024

Medicare pays $113.56 for 94450 nationally in the office. Local office rates run $98.93–$158.22.

Medicare rate · 94450

Hypoxia response test

Work RVUs
0.39
Total RVUs
3.40
Global days
XXX

National rate · 2026

$113.56

Office setting, before claim adjustments.

See every locality for 94450 →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 94450 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 94450 covers

This pulmonary function study evaluates how a patient's breathing responds when the inspired oxygen level is reduced under controlled testing conditions. It may be performed in a pulmonary function laboratory or outpatient facility, with pulmonary staff conducting the test and a physician or qualified health care professional interpreting the findings. The clinical question is the ventilatory response to hypoxia, rather than oxygen saturation during exertion or oxygen needs at simulated altitude.

Report 94450 when the documented service is a controlled assessment of breathing response to hypoxia. The record should support the test performed, the measurements obtained, and the interpretation. CMS recognizes separately priced professional and technical components: modifier 26 identifies the interpretation, modifier TC identifies the equipment and staff portion, and reporting without either modifier represents the global service. The professional and technical portions may be billed separately when furnished by different entities.

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 94450 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

$98.93 to $158.22

$98.93$128.57$158.22
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

94450 office and facility rates by payment locality
Payment localityOfficeFacility
Alabama$100.58Unavailable
Alaska*$125.92Unavailable
Arizona$110.30Unavailable
Arkansas$98.93Unavailable
Atlanta$115.46Unavailable
Austin$119.19Unavailable
Bakersfield$122.81Unavailable
Baltimore/Surr. Cntys$121.33Unavailable
Beaumont$104.54Unavailable
Brazoria$112.48Unavailable

94450 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.

$98.93

$140.45

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

View every state and territory as a table
94450 office rate range by state
State / territoryOffice rate rangeLocalities
AK$125.921
AL$100.581
AR$98.931
AZ$110.301
CA$122.69–$158.2229
CO$119.781
CT$121.741
DC$132.081
DE$112.301
FL$109.87–$119.673
GA$103.11–$115.462
GU$126.591
HI$126.591
IA$104.331
ID$104.921
IL$105.68–$117.364
IN$105.631
KS$103.381
KY$102.441
LA$102.10–$107.892
MA$118.76–$133.202
MD$114.77–$132.083
ME$105.12–$112.182
MI$105.10–$111.012
MN$115.501
MO$99.84–$108.803
MS$99.431
MT$113.561
NC$106.431
ND$112.771
NE$105.091
NH$117.461
NJ$123.34–$130.352
NM$105.601
NV$113.441
NY$108.21–$134.295
OH$104.941
OK$102.651
OR$112.77–$124.442
PA$105.36–$118.122
PR$114.631
RI$116.941
SC$105.821
SD$112.681
TN$103.921
TX$104.54–$119.198
UT$107.471
VA$111.48–$132.082
VI$114.631
VT$111.911
WA$118.67–$136.492
WI$108.471
WV$101.141
WY$113.221

How the 94450 rate is calculated

Each of 94450’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 · 94450

RVUs × geographic indexes × conversion factor

Work0.39

0.39 RVUs× 1.000 GPCI

Practice expense2.97

2.97 RVUs× 1.000 GPCI

Malpractice0.04

0.04 RVUs× 1.000 GPCI

Adjusted RVUs

3.4000

Conversion factor

$33.4009

Medicare rate

$113.56

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

Payment rules and modifiers for 94450

The CMS indicators that decide how 94450 is paid alongside other services.

CMS payment indicators · 94450

Hypoxia response test

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

94450 without 26 · national office

$113.56

Hypoxia response test

94450-26 · Professional component

$22.71

Pays only the interpretation and report.

When to use modifier 26

94450 compared with similar codes

Compare codes · National

4 codes, side by side

  • 94450

    Hypoxia response test0.39 wRVU

    $113.56

  • 94452

    Altitude simulation test0.3 wRVU

    $57.45−$56.11

  • 94453

    Altitude simulation0.39 wRVU

    $75.82−$37.74

  • 94618

    Pulmonary stress test0.47 wRVU

    $37.07−$76.49

How to choose

94452Altitude simulation test
Choose 94450 for a controlled test of breathing response to hypoxia. Choose 94452 when the study simulates altitude to evaluate oxygenation.
94453Altitude simulation
94453 adds supplemental oxygen titration during high altitude simulation testing; 94450 evaluates ventilatory response to hypoxia.
94618Pulmonary stress test
94618 evaluates physiologic response during pulmonary stress testing, such as a walk test. It does not represent controlled hypoxia testing.

Codes related to 94450

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

Codes related to 94450
CodeHow it relatesNational office range
Used instead
94452Altitude simulation testHigh altitude simulation testing evaluates oxygenation under simulated altitude conditions.$50.53–$78.91
94453Altitude simulationHigh altitude simulation testing with supplemental oxygen titration addresses oxygen needs at simulated altitude.$66.51–$103.80
94618Pulmonary stress testPulmonary stress testing assesses response to exercise rather than controlled hypoxia.$33.72–$47.34

94450 billing questions

How does 94450 differ from a high altitude simulation test?

94450 evaluates the breathing response to controlled hypoxia. High altitude simulation testing evaluates oxygenation under simulated altitude conditions, with or without supplemental oxygen titration.

Does 94450 include both testing and interpretation?

Reporting without a component modifier represents the global service. Modifier 26 identifies the professional interpretation, while modifier TC identifies the technical service, including equipment and staff.

What documentation supports reporting 94450?

Document the controlled hypoxia test performed, the measurements used to assess breathing response, and the interpreting clinician's findings.

When should modifier 26 or TC be used?

Use modifier 26 for the interpretation and modifier TC for the equipment and staff portion when billing those components separately. Report the service without either modifier when billing the global service.

Can exercise testing be reported instead of 94450?

A pulmonary stress test such as 94618 addresses physiologic response to exercise, including oxygen saturation monitoring. It is not a substitute when the documented service is a controlled assessment of breathing response to hypoxia.

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 94450PPRRVU2026_Oct_nonQPP.csv, line 12,388 (RVU26D)

Open CMS sourceHow we calculate rates

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