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The CPT® Code 80167 refers to a laboratory test specifically designed to monitor therapeutic levels of felbamate, which is an antiepileptic medication utilized in the treatment of various types of seizures. This test is crucial for therapeutic drug monitoring, as it aids healthcare providers in optimizing the dosage of felbamate to ensure its effectiveness while minimizing the risk of toxicity. Monitoring is particularly important because the therapeutic levels of felbamate can be influenced by the presence of other medications, such as barbiturates and phenytoin, which may alter its serum concentration when co-administered. The elimination half-life of felbamate ranges from 13 to 23 hours, indicating the time it takes for the concentration of the drug in the bloodstream to reduce by half. For effective treatment, serum concentration trough levels of felbamate should ideally be maintained between 30 to 60 mcg/mL. Levels exceeding 60 mcg/mL can lead to toxicity, which poses serious health risks, including life-threatening conditions such as aplastic anemia or liver failure. To perform this test, a blood specimen is collected just before the patient's next scheduled dose of felbamate. The collected sample is then centrifuged within two hours to separate the serum from the blood cells and is placed in a plastic vial for analysis. The concentration levels of felbamate are determined using quantitative liquid chromatography-tandem mass spectrometry, a precise method that allows for accurate measurement of drug levels in the serum.
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The laboratory test associated with CPT® Code 80167 is indicated for the following conditions:
The procedure for conducting the laboratory test for felbamate levels involves several critical steps:
After the laboratory test is completed, the results will be analyzed to determine the serum concentration of felbamate. Healthcare providers will review these results to assess whether the patient's drug levels are within the optimal therapeutic range of 30-60 mcg/mL. If the levels are found to be above 60 mcg/mL, indicating potential toxicity, the provider may need to adjust the dosage or consider alternative treatment options. Continuous monitoring may be required to ensure patient safety and effective management of seizure control. Additionally, any signs of adverse effects, such as symptoms of aplastic anemia or liver dysfunction, should be closely monitored following the test results.
| Short Descr | DRUG ASSAY FELBAMATE | Medium Descr | DRUG ASSAY FELBAMATE | Long Descr | Felbamate | Status Code | Statutory Exclusion (from MPFS, may be paid under other methodologies) | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 9 - Not Applicable | Multiple Procedures (51) | 9 - Concept does not apply. | Bilateral Surgery (50) | 9 - Concept does not apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 9 - Concept does not apply. | Co-Surgeons (62) | 9 - Concept does not apply. | Team Surgery (66) | 9 - Concept does not apply. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | CLIA Waived (QW) | No | APC Status Indicator | Conditionally packaged laboratory tests | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | none | MUE | 1 |
| 90 | Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number. | Q4 | Service for ordering/referring physician qualifies as a service exemption |
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| 2021-01-01 | Added | Code added. |
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