Cortisol test names and codes: what each lab order is called

Cortisol goes by many names on lab menus, order forms and result reports. “Cortisol”, “serum cortisol”, “AM cortisol”, “free cortisol” and “24-hour urinary cortisol” can all show up, and they are not the same test. This page sorts the names so you can tell what an order actually measures.

It also answers the other thing people search for here: the billing code for a cortisol test.

Cortisol

One blood draw for one cortisol result. It can’t diagnose or rule out an adrenal condition by itself.

$109

See this test at HealthLabs

Price checked November 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.

Names for a cortisol test in blood

MedlinePlus lists several other names for the cortisol test: blood cortisol, plasma cortisol and cortisol serum. These all describe a sample from a vein. The lab separates the liquid part of the blood (serum or plasma) and measures cortisol in it.

A few things on the label change the meaning:

• Total or free. Unless a test says “free”, a blood cortisol is normally the total, which includes cortisol attached to carrier proteins. About 90% of blood cortisol is attached to a carrier protein called CBG, and only about 5% is free (Diagnostics, 2023). A true free cortisol in blood is a separate, more specialized measurement. See free and total cortisol.
• AM, PM or random. Cortisol is highest in the morning and much lower around 4 p.m., and MedlinePlus says blood samples are usually taken at both times. An “AM cortisol” is the morning sample. A “random” cortisol is an untimed one. A laboratory review says that for assessing Cushing’s syndrome, random specimens are of no use. See AM and PM timing.
• Old method names. MedlinePlus also lists “cortisol competitive protein binding assay” and “cortisol fluorometric assay” among the other names. These are older ways of measuring cortisol. A 2024 review in Endocrine Reviews says serum cortisol was once measured with a nonspecific fluorometric assay and is now commonly measured with automated immunoassays, so you are unlikely to see those older names on a current order.

Names for urine and saliva tests

MedlinePlus lists these among the other names for a cortisol test:

• 24-hour urinary free cortisol (UFC), also called urinary cortisol or 24-hour urinary cortisol excretion. You collect all your urine for 24 hours. It measures free cortisol, the part that passes into urine.
• Salivary cortisol, and late-night salivary cortisol, a saliva sample taken in the late evening. NIDDK describes it as the test that checks whether cortisol drops at night the way it normally does.

You may also see salivary cortisone. Cortisone is the inactive form that cortisol is converted to, and a 2026 review says that, measured by mass spectrometry, it can be used in place of salivary cortisol for late-night screening. A 2023 review notes that it isn’t routinely available in all laboratories. Hair cortisol is an emerging method, and the 2026 review says it has no validated thresholds for routine clinical use. The saliva, urine and hair page compares them.

Related adrenal tests that appear next to cortisol

Some names sit beside cortisol on a work-up. These are usually arranged by a clinician.

Name on the order	What it is
ACTH, adrenocorticotropic hormone, corticotropin	A blood test for the pituitary hormone that tells the adrenal glands to make cortisol. MedlinePlus says it is usually compared with a cortisol level. See ACTH blood test.
Dexamethasone suppression test (low-dose, or 1 mg overnight)	You take dexamethasone around 11 p.m. and have blood drawn the next morning, about 8 a.m. (NIDDK). Used when Cushing’s syndrome is suspected.
ACTH stimulation test, also cosyntropin stimulation test or ACTH 1-24 test	A health care professional injects synthetic ACTH and takes blood before and 30 or 60 minutes after (NIDDK). Used when adrenal insufficiency is suspected. A 2023 review gives the last two names for the same test, and a 2024 review calls the drug tetracosactide.
CRH stimulation test, dexamethasone-CRH test, insulin tolerance test	Follow-up tests a clinician orders when earlier results are unclear (NIDDK). The insulin tolerance test needs a health professional present throughout.

None of these is a do-it-yourself test, and a single cortisol blood draw can’t replace them. A single blood cortisol can’t diagnose or rule out Cushing’s syndrome or adrenal insufficiency.

Match the name to your question

Your question	Names you may see	Who usually arranges it
Is my cortisol low in the morning?	Cortisol (serum), AM cortisol, often with ACTH	A clinician
Does my level fall through the day?	Cortisol AM and PM, two timed samples	You or a clinician
Is my cortisol too high?	24-hour urinary free cortisol, late-night salivary cortisol, dexamethasone suppression test	A clinician
How much is the active (free) hormone?	Free cortisol (urine, saliva or a specialized blood test)	A clinician

For the full reasoning behind each row, see testing for low cortisol and testing for high cortisol.

Names can mislead

Check what a name is attached to before you trust it. “Cortisol” on a report can mean total or free cortisol, and they are very different amounts. If a name and a number don’t seem to fit, ask the lab which cortisol the report shows.

Reports also vary in units and in the reference range printed beside the result, because each lab sets its own. The cortisol units converter helps if one source uses µg/dL and another uses nmol/L. The normal range page lists published ranges and where they come from.

What the seller calls its tests

The seller’s single blood test is listed as “Cortisol”, and its page doesn’t say whether it reports total or free cortisol. If that matters for your question, check before you order. The two-sample test is listed as “Cortisol, AM & PM”. Its page gives a morning window and a later window, but it also mentions a second sample “at night”, and it doesn’t say whether the two draws are one visit or two. Check that before you order, and follow the timing on your lab order. The ACTH test is listed under its full name, adrenocorticotropic hormone.

• Cortisol AM and PMTwo timed samples. Check the second draw time before you order $129 See this test at HealthLabs
• ACTHOften compared with a cortisol level $49 See this test at HealthLabs

Sold by HealthLabs. Prices checked November 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.

Billing codes

People search for a cortisol code to check an insurance claim or an itemized bill. Billing codes for the test and for the reason it was ordered are assigned by the lab and the ordering clinic. This page doesn’t list them, because the right code depends on the exact test billed. Ask the lab’s billing office, your clinician’s office or your insurer which code applies to your order.

Questions people ask

What is the cortisol test called on a lab order?

Most often “Cortisol” or “Cortisol, serum”, sometimes with AM or PM added. MedlinePlus lists blood cortisol, plasma cortisol and cortisol serum as other names. The version for urine or saliva has “urinary”, “24-hour” or “salivary” in the name.

Is “cortisol, free” the same as cortisol?

No. Free cortisol is the unbound part. A standard blood cortisol reports total cortisol, which includes the part attached to carrier proteins. See free and total cortisol.