Order Carbon Dioxide (CO2) Blood Test: Bicarbonate from JustLabs for $5 ($23 all-in for a single-test order: $5 + one $18 lab & physician order fee per order). Price includes lab processing at Quest Diagnostics. No insurance required.
This test measures total carbon dioxide in your blood, which is mostly bicarbonate, a base that helps keep your blood's pH in balance. Low or high values point clinicians toward acid-base problems.
Carbon dioxide is a waste product of turning food into energy. Most of it travels in the blood as bicarbonate (HCO3), an electrolyte that helps control the body's acid-base balance. Your blood carries carbon dioxide to your lungs to be breathed out, and your lungs and kidneys together help keep your blood's pH in balance.
On a lab report this test is usually called CO2 or bicarbonate. It is not the same as the arterial blood gas test done in hospitals: it is a routine serum electrolyte, most often measured with sodium, potassium and chloride. A low value suggests the body is dealing with too much acid, as in kidney disease, diabetic ketoacidosis or long-lasting diarrhea; a high value suggests too much base, as after prolonged vomiting, or long-term lung disease.
Because carbon dioxide can escape from an opened tube and lower the result, Quest handles this sample in a full, unopened, spun gel tube.
CO2 is also included in our Basic Metabolic Panel, Comprehensive Metabolic Panel and Renal Function Panel. Choose this single test when you only need to re-check CO2, for example to follow up a previous result or to monitor a condition your clinician is tracking.
Price
$5
All-in
$23
incl. $18 lab & physician fee
Results
1-3 business days
Fasting
Not Required
What's Measured
What This Test Measures
This test measures total carbon dioxide (CO2 content) in serum, most of which is bicarbonate (HCO3). It reflects the body's acid-base balance. Quest's directory lists the aliases CO2 content, HCO3 and bicarbonate for this code. It is a venous serum measurement and does not replace an arterial blood gas.
Who Should Consider This Test
People re-checking a CO2 that was low or high on a previous panel; people with kidney, lung or liver disease, diabetes, or prolonged vomiting or diarrhea whose clinician follows their acid-base balance; and people taking medicines that can affect bicarbonate.
Health Insights
Conditions Screened
Related Symptoms
When to Get Tested
Any time of day; no fasting is needed. Recent prolonged vomiting or diarrhea can move the result, so if you are trying to see your baseline, test once you are back to your usual routine.
No fasting needed. How to prepare for your blood test →
Understanding Your Results
Quest's reference range for this code is 20-32 mmol/L. A low CO2 can point to metabolic acidosis, from kidney disease, diabetic ketoacidosis, long-lasting diarrhea or liver disease, to Addison disease or shock, or to respiratory alkalosis from hyperventilation. A high CO2 can point to metabolic alkalosis, for example after vomiting or dehydration, to lung diseases in which carbon dioxide is retained, or to Cushing syndrome. Some medicines move CO2 as well, so an abnormal value does not always mean a condition needing treatment. Clinicians read CO2 with sodium, chloride and potassium, and may order further tests. JustLabs results are informational; review them with a clinician.
What to Expect
After placing your order, we send it straight to Quest Diagnostics — there is no consent form to sign and no partner email to wait for. Your requisition is usually ready to download from your dashboard within about an hour, and you can book your blood draw at any Quest Diagnostics location.
The blood draw typically takes just a few minutes. Results are usually available within 1-3 business days and will appear in your secure JustLabs dashboard.
Our results include reference ranges and easy-to-understand indicators showing whether your values are within normal limits.
How much does the CO2 (Bicarbonate) test cost?
The CO2 (Bicarbonate) test costs $5 at JustLabs — $23 all-in, since the $18 lab & physician order fee is charged once per order, however many tests you add. The price is fixed before your blood draw; no insurance or doctor visit needed.
| Option | Price | Order all-in | Notes |
|---|---|---|---|
| CO2 (Bicarbonate) at JustLabsDrawn at Quest Diagnostics | $5 | $23 | Includes the one $18 fee, charged once per order |
Paying with an HSA or FSA? See which lab tests qualify
Frequently Asked Questions
Hospital cash price: $120–$200
$5
+ $18 order fee · $23 all-inOne $18 fee per order covers your Quest blood draw and the independent physician order, however many tests you add.
- Results in 1-3 business days
- No fasting required
- Physician order included
No insurance needed · HSA/FSA eligible
- Physician-ordered
- CLIA-certified Quest lab
- Drawn at Quest Diagnostics
Need Help Choosing?
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