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Procedure price report · Laboratory - Chemistry and Hematology

Breathing gas test of oxygen use and carbon dioxide output

CPT 94681the billing code this page is about

Exhaled air is collected and analyzed to measure how much oxygen the body takes up, how much carbon dioxide it gives off, and the share of oxygen extracted from each breath.

Hospitals typically charge $405 cash for this outpatient procedure — the median across 885 hospitals that filed a usable cash price; the average of the middle 60% is $406. Most fall between $186 and $671 (20th–80th percentile).

Hospitals
885
States
49
Filings dated
Jun 2024 – Sep 2026
Computed
September 25, 2026
Prices checked
through September 25, 2026

Median: half of hospitals filed less, half more — and it is a price some hospital actually filed. Average of the middle 60%: the mean of the prices between the 20th and 80th percentiles. We never publish the plain average, the lowest or the highest price: the extremes in hospital price files are chargemaster artefacts, not prices anyone pays.

What hospitals charge, from cheapest to most expensive

Cash price percentiles, outpatient, across 885 hospitals. Each figure is a price a hospital filed. 10th: one in ten hospitals charges less; 25th: a quarter charge less; Median: half charge less; 75th: three quarters charge less; 90th: nine in ten charge less.
10th25thMedian75th90th
$105$252$405$592$932

The most expensive tenth of hospitals charges at least 8.9× what the cheapest tenth charges ($105 vs $932).

How the prices are spread

$57 – $78: 21 hospitals$57$78 – $107: 26 hospitals$107 – $146: 32 hospitals$107$146 – $200: 67 hospitals$200 – $273: 50 hospitals$200$273 – $373: 169 hospitals$373 – $509: 199 hospitals$373$509 – $696: 111 hospitals$696 – $952: 81 hospitals$696$952 – $1,301: 41 hospitals$952median $405price bands are equal on a log scale
Hospitals per price band (797 of 885 — the bands cover the 5th to 95th percentile)
FromToHospitals
$57$7821
$78$10726
$107$14632
$146$20067
$200$27350
$273$373169
$373$509199
$509$696111
$696$95281
$952$1,30141

Against Medicare

Medicare pays (OPPS 2026, national rate)$381
Median cash price$405
Cash as a multiple of Medicare1.06×

The Medicare figure is the national unadjusted OPPS rate for this code — what Medicare itself pays a hospital before local wage adjustment. It is a benchmark, not a price anyone is charged.

By state

The median cash price in each state, against the national median of $405.

Alaska: 1 hospital filed a usable price — fewer than 10, so no figureAKMaine: 3 hospitals filed a usable price — fewer than 10, so no figureMEVermont: 1 hospital filed a usable price — fewer than 10, so no figureVTNew Hampshire: 1 hospital filed a usable price — fewer than 10, so no figureNHWashington: median $374 across 13 hospitalsWA$374Idaho: 7 hospitals filed a usable price — fewer than 10, so no figureIDMontana: 1 hospital filed a usable price — fewer than 10, so no figureMTNorth Dakota: 2 hospitals filed a usable price — fewer than 10, so no figureNDMinnesota: median $297 across 21 hospitalsMN$297Illinois: median $346 across 28 hospitalsIL$346Wisconsin: median $489 across 33 hospitalsWI$489Michigan: median $308 across 41 hospitalsMI$308New York: median $369 across 36 hospitalsNY$369Massachusetts: 5 hospitals filed a usable price — fewer than 10, so no figureMAOregon: median $391 across 19 hospitalsOR$391Nevada: 3 hospitals filed a usable price — fewer than 10, so no figureNVWyoming: 3 hospitals filed a usable price — fewer than 10, so no figureWYSouth Dakota: 2 hospitals filed a usable price — fewer than 10, so no figureSDIowa: median $247 across 27 hospitalsIA$247Indiana: median $1,243 across 21 hospitalsIN$1,243Ohio: median $394 across 53 hospitalsOH$394Pennsylvania: median $538 across 39 hospitalsPA$538New Jersey: median $345 across 22 hospitalsNJ$345Connecticut: 5 hospitals filed a usable price — fewer than 10, so no figureCTRhode Island: 4 hospitals filed a usable price — fewer than 10, so no figureRICalifornia: median $459 across 81 hospitalsCA$459Utah: median $415 across 10 hospitalsUT$415Colorado: median $207 across 20 hospitalsCO$207Nebraska: median $347 across 10 hospitalsNE$347Missouri: median $389 across 22 hospitalsMO$389Kentucky: median $326 across 13 hospitalsKY$326West Virginia: 3 hospitals filed a usable price — fewer than 10, so no figureWVVirginia: median $410 across 21 hospitalsVA$410Maryland: 7 hospitals filed a usable price — fewer than 10, so no figureMDDelaware: no hospital in the corpus filed a usable priceDEArizona: median $206 across 12 hospitalsAZ$206New Mexico: 9 hospitals filed a usable price — fewer than 10, so no figureNMKansas: median $353 across 16 hospitalsKS$353Arkansas: median $360 across 10 hospitalsAR$360Tennessee: median $374 across 12 hospitalsTN$374North Carolina: median $528 across 11 hospitalsNC$528South Carolina: median $332 across 10 hospitalsSC$332Oklahoma: median $217 across 28 hospitalsOK$217Louisiana: median $116 across 15 hospitalsLA$116Mississippi: 9 hospitals filed a usable price — fewer than 10, so no figureMSAlabama: median $198 across 10 hospitalsAL$198Georgia: median $417 across 34 hospitalsGA$417Hawaii: 7 hospitals filed a usable price — fewer than 10, so no figureHITexas: median $473 across 85 hospitalsTX$473Florida: median $334 across 39 hospitalsFL$334
Cash price by state, most expensive first. National median $405. A state needs at least 10 hospitals with a usable price to show a figure.
StateHospitalsMedianvs national20th–80th
Indiana IN21$1,243+207%$308 – $1,574
Pennsylvania PA39$538+33%$365 – $798
North Carolina NC11$528+30%$254 – $756
Wisconsin WI33$489+21%$238 – $677
Texas TX85$473+17%$293 – $789
California CA81$459+13%$338 – $917
Georgia GA34$417+3%$345 – $1,636
Utah UT10$415+3%$186 – $519
Virginia VA21$410+1%$278 – $410
Ohio OH53$394−3%$330 – $931
Oregon OR19$391−4%$23 – $608
Missouri MO22$389−4%$353 – $575
Washington WA13$374−8%$369 – $833
Tennessee TN12$374−8%$319 – $511
New York NY36$369−9%$318 – $606
Arkansas AR10$360−11%$122 – $518
Kansas KS16$353−13%$300 – $625
Nebraska NE10$347−14%$163 – $597
Illinois IL28$346−15%$200 – $1,105
New Jersey NJ22$345−15%$340 – $752
Florida FL39$334−18%$252 – $592
South Carolina SC10$332−18%$177 – $409
Kentucky KY13$326−19%$72 – $395
Michigan MI41$308−24%$160 – $468
Minnesota MN21$297−27%$136 – $299
Iowa IA27$247−39%$24 – $454
Oklahoma OK28$217−46%$20 – $591
Colorado CO20$207−49%$186 – $660
Arizona AZ12$206−49%$92 – $458
Alabama AL10$198−51%$112 – $333
Louisiana LA15$116−71%$74 – $206
Mississippi MS9not enough hospitals filed a usable price
New Mexico NM9not enough hospitals filed a usable price
Hawaii HI7not enough hospitals filed a usable price
Idaho ID7not enough hospitals filed a usable price
Maryland MD7not enough hospitals filed a usable price
Connecticut CT5not enough hospitals filed a usable price
Massachusetts MA5not enough hospitals filed a usable price
Rhode Island RI4not enough hospitals filed a usable price
Maine ME3not enough hospitals filed a usable price
Nevada NV3not enough hospitals filed a usable price
West Virginia WV3not enough hospitals filed a usable price
Wyoming WY3not enough hospitals filed a usable price
North Dakota ND2not enough hospitals filed a usable price
South Dakota SD2not enough hospitals filed a usable price
Alaska AK1not enough hospitals filed a usable price
Montana MT1not enough hospitals filed a usable price
New Hampshire NH1not enough hospitals filed a usable price
Vermont VT1not enough hospitals filed a usable price

Hospitals like yours

The same distribution cut by the kind of hospital. Hospital type and ownership come from CMS; a hospital counts as part of a system when its price file is shared with at least one other hospital under the same brand. The national median is $405.

Cash price by hospital segment. A segment needs at least 20 hospitals to show a figure.
SegmentHospitalsMedian20th–80th
Hospital type
Acute care706$410$186 – $671
Children’s42$357$277 – $824
Critical access135$405$160 – $662
Ownership
For-profit100$473$186 – $1,015
Government119$337$182 – $554
Non-profit664$410$186 – $669
System affiliation
Part of a system764$413$188 – $677
Independent121$333$126 – $649

Cash price vs list price

Median list price (chargemaster)$734
Median cash price$405
Cash as a share of list, median hospital62%

At the typical hospital, asking for the cash price cuts the list price by about 38%. The share is the median of each hospital’s own cash ÷ list ratio, over hospitals that filed both — not the ratio of the two medians above.

The same procedure, inpatient

617 hospitals filed a usable inpatient cash price for this code. The median is $419 and the average of the middle 60% is $431; most fall between $251 and $698.

Cash price percentiles, inpatient, across 617 hospitals. Each figure is a price a hospital filed. 10th: one in ten hospitals charges less; 25th: a quarter charge less; Median: half charge less; 75th: three quarters charge less; 90th: nine in ten charge less.
10th25thMedian75th90th
$124$279$419$614$931

The most expensive tenth of hospitals charges at least 7.5× what the cheapest tenth charges ($124 vs $931).

Of the 681 hospitals that filed this code inpatient, 617 gave a usable cash price; 39 carried a plausibility flag, 1 filed a number their own filing marks as not a price, 0 gave an estimate, and 24 a list price only.

How complete is this

885 of the 3,956 hospitals with a price file in our corpus (22%) filed a usable outpatient cash price for this code, and those are the hospitals every figure on this page is computed from.

What the 954 hospitals that filed this code at all gave us
Usable cash price — counted885
Cash price carrying a plausibility flag — shown on the compare tool, excluded here47
A number the filing itself marks as not a price (a placeholder, a ratio) — excluded0
An estimate rather than a filed cash price — excluded0
A list price only, no cash figure — excluded22
Hospitals that filed this code954

Sections not shown for this setting

  • Since our last snapshot: there is no earlier snapshot at least 90 days older than this one yet.

We last checked these hospitals’ price files for changes between September 4, 2026 and September 25, 2026; the figures were computed September 25, 2026 from filings loaded through September 25, 2026. The percentiles and averages use only the “counted” row.

Related procedures

Part of the Laboratory - Chemistry and Hematology family.

Hospitals file this code under descriptions such as O2 Uptk Exp Gas Alys W/Co2 Output % O2 Xtrc|PROFESSIONAL COMPONENT.

Method

Source
The machine-readable price files every U.S. hospital is required by CMS to publish, parsed per hospital. Nothing is surveyed, sampled or modelled.
What counts
One cash (self-pay) price per hospital for this code and setting. A hospital’s own filing can rule its number out — a placeholder, a “not applicable” note, a list price standing in for cash — and our plausibility checks can flag a price far below what every other hospital files. Both kinds are disclosed above and excluded from the statistics; on the compare tool a flagged price is still shown.
Statistics
Percentiles are discrete: each is a price some hospital filed. The average is the mean of the prices between the 20th and 80th percentiles. We never publish the plain mean, the minimum or the maximum. A state needs 10 hospitals and a segment 20 to show a figure; otherwise the row shows its count and no number. Medicare is the national unadjusted OPPS rate where one exists.
Names
Procedure names on these pages are our own plain-language titles, not the AMA’s copyrighted CPT descriptors. The code is the identity.

The full rules — sources, statistics, thresholds, limitations — are on the methodology page.

Download this page’s figures: JSON · CSV. Aggregates only — the per-hospital prices are on the compare tool.

Cite: HospitalRates.com, “Breathing gas test of oxygen use and carbon dioxide output (CPT 94681) — cash price report,” computed September 25, 2026. https://hospitalrates.com/procedures/cpt-94681-breathing-gas-test-of-oxygen-use-and-carbon-dioxide-output