CPT code 80400: ACTH panel, two cortisol measurements2026 Medicare lab fee · Clinical Laboratory Fee Schedule
An adrenal insufficiency assessment panel that evaluates cortisol response to ACTH and includes two cortisol measurements.
Medicare pays $32.62 for 80400 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
$32.62
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
- CMS updates
- Quarterly
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 80400 covers
This endocrine laboratory panel evaluates adrenal insufficiency through ACTH stimulation and includes two cortisol assays. In the usual stimulation sequence, cortisol is measured before and after ACTH administration so the ordering clinician can assess the adrenal response. Clinical laboratories report the panel as a single service, with the cortisol assays represented within the panel rather than as separate units of 80400.
Report one unit for the panel. Medicare pays 80400 only under the Clinical Laboratory Fee Schedule (CLFS), at one national rate across localities with no geographic or office-versus-facility adjustment. The 2026 national CLFS amount is $32.62, unchanged since 2020. The code is excluded from the physician fee schedule by statute, and Medicare pays the test through the CLFS.
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 80400
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 80400. 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 80400 with status X (excluded by statute), so the test itself is paid only from the CLFS.
80400 on the lab fee schedule since 2020
80400 · CLFS 2026 Q4 (current)
$32.62
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.
80400 compared with similar tests
- 80402ACTH stimulation21-hydroxylase deficiency$86.96
- Both codes are ACTH stimulation panel codes. Code 80400 identifies the adrenal insufficiency panel that includes two cortisol measurements.
- 80406ACTH stimulation3-beta-HSD deficiency$78.26
- Both codes are ACTH stimulation panel codes. Code 80400 identifies the adrenal insufficiency panel that includes two cortisol measurements.
- 82533CortisolTotal hormone measurement$16.30
- 82533 is a cortisol assay code; 80400 represents an adrenal insufficiency ACTH stimulation panel that includes two cortisol assays.
80400 billing questions
When should 80400 be selected?
Use it for an ACTH stimulation panel assessing adrenal insufficiency that includes two cortisol measurements. Select among ACTH stimulation panel codes according to the applicable panel protocol.
How many units should be reported?
Report one unit of 80400 for the panel. The two cortisol assays are included in the panel.
Can the cortisol assays also be billed separately?
The two cortisol assays are represented within this panel. Do not report them as separate components of the same panel.
Is modifier 26 appropriate?
Medicare pays this test through the CLFS, not the physician fee schedule. The code has no separately payable physician interpretation component.
How does Medicare pay for this panel?
Medicare pays one national CLFS amount for the code, with no locality or office-versus-facility adjustment. The amount has remained unchanged since 2020.
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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