CPT code 80156: Carbamazepine level, total concentration2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures total carbamazepine to monitor antiseizure treatment and assess suspected toxicity, breakthrough seizures, or response to a dose change.
Medicare pays $14.57 for 80156 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
$14.57
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 80156 covers
The assay measures total carbamazepine, including the protein-bound and unbound portions, rather than only the free fraction or the 10,11-epoxide metabolite. Clinicians use the result when monitoring carbamazepine treatment, evaluating suspected adverse effects or toxicity, investigating breakthrough seizures, or assessing a dose change. Clinical laboratories perform and report the test; neurologists and other clinicians treating seizure disorders interpret the result with medication history and clinical findings.
Report 80156 for a total carbamazepine measurement; use 80157 for the free fraction and 80161 for the metabolite. Medicare pays this test only under the CLFS. Its national amount is the same in every state and locality, with no geographic or office-versus-facility adjustment. The 2026 national CLFS amount is $14.57, unchanged since 2020.
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 80156
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 80156. 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 80156 with status X (excluded by statute), so the test itself is paid only from the CLFS.
80156 on the lab fee schedule since 2020
80156 · CLFS 2026 Q4 (current)
$14.57
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.
80156 compared with similar tests
- 80157Carbamazepine levelUnbound carbamazepine$13.25
- 80157 measures only the free, unbound carbamazepine fraction; 80156 measures total carbamazepine.
- 80161Carbamazepine metabolite10,11-epoxide$18.64
- 80161 measures carbamazepine’s 10,11-epoxide metabolite, not the parent drug measured by 80156.
- 80164Valproate levelTotal concentration$13.54
- 80164 measures total valproic acid. Use it when that medication’s concentration is being assessed, not as a substitute for a carbamazepine level.
80156 billing questions
When should 80156 be used instead of 80157?
Use 80156 for total carbamazepine. Code 80157 is for the free, unbound fraction when that specific measurement is ordered.
How does 80156 differ from 80161?
80156 measures total carbamazepine, while 80161 measures its 10,11-epoxide metabolite. Select the assay matching the analyte ordered.
Can total carbamazepine and its metabolite be tested together?
They measure different analytes and may be ordered together when a clinician is evaluating carbamazepine exposure or possible toxicity. Report each performed assay separately.
What does the total carbamazepine measurement include?
It includes both protein-bound and unbound carbamazepine, unlike the free-fraction measurement reported with 80157.
How does Medicare pay for 80156?
Medicare pays 80156 under the CLFS at one national amount, with no geographic or office-versus-facility adjustment. It is paid only from the CLFS.
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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