CPT code 80183: Oxcarbazepine level, quantitative concentration assay2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Quantitative oxcarbazepine concentration testing supports therapeutic drug monitoring for patients receiving the medication and review of treatment exposure.
Medicare pays $13.25 for 80183 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
$13.25
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 7 sections
What 80183 covers
80183 identifies a quantitative laboratory measurement of oxcarbazepine concentration. It is used in therapeutic drug monitoring for patients receiving oxcarbazepine, with results interpreted in the context of the patient's treatment and clinical status. A clinician may use the result when reviewing drug exposure or considering treatment adjustments. Laboratories perform and report the assay for clinicians managing antiseizure therapy.
Report 80183 for the quantitative oxcarbazepine assay. The code is paid under the Medicare CLFS at one national amount that applies across states and localities, without geographic or office-versus-facility adjustment. The 2026 national amount is $13.25, unchanged from 2020 through 2025. Medicare pays this test only through the CLFS; it is excluded from the physician fee schedule by statute.
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 80183
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 80183. 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 80183 with status X (excluded by statute), so the test itself is paid only from the CLFS.
80183 on the lab fee schedule since 2020
80183 · CLFS 2026 Q4 (current)
$13.25
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.
80183 compared with similar tests
- 80175Lamotrigine levelQuantitative drug assay$13.25
- 80175 identifies a lamotrigine assay. Choose it when lamotrigine is measured; 80183 is specific to oxcarbazepine.
- 80177Levetiracetam levelQuantitative concentration$13.25
- 80177 identifies a levetiracetam assay, not an oxcarbazepine assay. Select the code for the medication tested.
- 80185Phenytoin levelTotal drug concentration$13.25
- 80185 measures total phenytoin. It is not interchangeable with 80183, which measures oxcarbazepine.
80183 billing questions
What does 80183 measure?
It identifies a quantitative laboratory assay of oxcarbazepine concentration.
How does 80183 differ from 80175 or 80177?
80183 is for oxcarbazepine, 80175 is for lamotrigine, and 80177 is for levetiracetam. Select the code for the drug measured.
Which Medicare fee schedule pays 80183?
Medicare pays 80183 through the CLFS; the test is excluded from the physician fee schedule by statute.
Does Medicare payment vary by locality or setting?
No. The CLFS amount is national and applies across localities, without an office-versus-facility adjustment.
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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