CPT code 82374: Blood CO2, bicarbonate level2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures carbon dioxide, primarily reflecting bicarbonate, in blood to assess acid-base balance and support evaluation of metabolic or renal disorders.
Medicare pays $4.88 for 82374 under the 2026 Clinical Laboratory Fee Schedule: one national amount, the same in every state and setting.
Medicare lab fee · CLFS 2026 Q4
National CLFS amount
$4.88
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2020
- Unchanged
- QW · CLIA-waived test
- $4.88
Medicare pays the lesser of the lab’s charge and this amount. Patients usually owe no Part B deductible or coinsurance for covered clinical lab tests.
On this page 8 sections
What 82374 covers
This chemistry test measures carbon dioxide in blood, with the result largely reflecting bicarbonate. It is commonly ordered as part of evaluation or monitoring of acid-base disturbances, electrolyte abnormalities, and renal or metabolic conditions. Laboratories generally perform it on a blood specimen, often serum or plasma, and report the result to the ordering clinician. It may be ordered individually or included among the tests in a basic or comprehensive metabolic panel.
Report 82374 for the individual assay when it is not represented by a panel code. CMS also lists a CLIA-waived version with modifier QW for sites holding a CLIA certificate of waiver. Medicare pays the test only through the CLFS; the 2026 national amount is $4.88 and has remained unchanged since 2020. The amount is the same across states and localities, without an office-versus-facility difference.
This summary was written with AI assistance from CMS Clinical Laboratory Fee Schedule data. Amounts on this page come directly from CMS files.
How Medicare pays 82374
Clinical lab tests aren’t priced like physician services. They’re paid from their own fee schedule, with its own rules. See the whole lab fee schedule.
One national amount
CMS sets a single Clinical Laboratory Fee Schedule amount for 82374. There’s no geographic (GPCI) adjustment, so it pays the same in every state and payment locality.
No office or facility rate
Lab tests aren’t built from relative value units, so there’s no office and facility split: the place of service doesn’t change the CLFS amount.
Updated every quarter
CMS republishes the CLFS each quarter. New tests, often proprietary laboratory analyses (PLA codes), join during the year; existing amounts are updated each January.
Excluded from the physician fee schedule
The physician fee schedule lists 82374 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 82374 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $4.88.
82374 on the lab fee schedule since 2020
82374 · CLFS 2026 Q4 (current)
$4.88
Unchanged since Jan 1, 2020
27 quarterly CLFS releases on file, first CLFS 2020 Q1. A code missing from a quarter wasn’t on that release.
82374 compared with similar tests
- 80048Basic metabolic panelTotal calcium$8.46
- This is the basic metabolic panel, which includes carbon dioxide along with other chemistry tests. Use 82374 for an individual assay rather than separately coding a panel component.
- 80053Metabolic panelFourteen blood chemistry tests$10.56
- This is the comprehensive metabolic panel and includes carbon dioxide among its tests. Choose it when the performed tests meet the panel requirements, rather than reporting 82374 separately for that component.
- 82375CarboxyhemoglobinQuantitative blood level$12.32
- 82375 measures carboxyhemoglobin in blood, not total carbon dioxide or bicarbonate. Select based on the analyte measured.
82374 billing questions
When should 82374 be reported instead of a metabolic panel?
Report 82374 when the blood carbon dioxide assay is performed and reported individually. When the performed tests meet the requirements for a basic or comprehensive metabolic panel, report the applicable panel rather than separately coding its included carbon dioxide test.
What does the result represent?
The blood carbon dioxide result largely reflects bicarbonate and is used in assessing acid-base balance. It is not a carboxyhemoglobin measurement.
When is modifier QW appropriate?
CMS lists a CLIA-waived version of this test with modifier QW. Use QW for the waived test performed at a site holding a CLIA certificate of waiver.
How does Medicare pay for 82374?
Medicare pays 82374 through the CLFS at one national amount, with no locality or office-versus-facility adjustment. The test is paid only through the CLFS.
How does 82374 differ from 82375?
82374 measures blood carbon dioxide, which largely reflects bicarbonate. 82375 measures carboxyhemoglobin.
Where this amount comes from
FeeBase reads lab amounts directly from the CMS Clinical Laboratory Fee Schedule file for the quarter: one row per code, with its payment indicator and national amount. Contractor-priced tests are labeled, never given a made-up amount. Amounts are Medicare payment limits, not a patient’s bill or a commercial rate.
CMS CLFS 2026 Q4 · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file line behind this amount
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