How To Use CPT Code 80161

CPT 80161 describes the laboratory test used to measure the level of the –10,11–epoxide metabolite of carbamazepine in a patient’s specimen. This article will cover the description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, similar codes and billing examples.

1. What is CPT Code 80161?

CPT 80161 can be used to describe the laboratory test performed to quantify the level of the –10,11–epoxide metabolite of carbamazepine in a patient’s specimen, such as serum. Carbamazepine is an anticonvulsant medication used for the treatment of epilepsy and other neurological and psychiatric disorders. This test helps monitor the potential toxicity of the medication by measuring the level of carbamazepine –10,11–epoxide in the patient’s specimen.

2. Official Description

The official description of CPT code 80161 is: ‘Carbamazepine; -10,11-epoxide.’

3. Procedure

1. The lab analyst performs the technical steps to measure the level of carbamazepine –10,11–epoxide in the patient’s specimen, typically serum or plasma.
2. The specimen is prepared for analysis using an automated analytical instrument, such as liquid chromatography–tandem mass spectrometry (LC–MS/MS).
3. The instrument separates the components of the specimen through a high-pressure liquid chromatograph and quantifies the individual components in a mass spectrometer based on mass-to-charge ratio.
4. The quantitative result for carbamazepine –10,11–epoxide is provided by the instrument.

4. Qualifying circumstances

CPT 80161 is typically ordered for patients taking carbamazepine for seizures or other neurological or psychiatric disorders who exhibit symptoms of possible toxic levels of the metabolite carbamazepine –10,11–epoxide, despite appropriate therapeutic levels of total carbamazepine. The most common specimen used for this test is serum or plasma.

5. When to use CPT code 80161

CPT code 80161 should be used when a quantitative test is performed to measure the level of carbamazepine –10,11–epoxide in the patient’s specimen. This code is appropriate when monitoring the potential toxicity of carbamazepine in patients taking the medication for seizures or other neurological or psychiatric disorders.

6. Documentation requirements

To support a claim for CPT 80161, the documentation should include:

• Indication for the test, such as symptoms of possible toxic levels of carbamazepine –10,11–epoxide
• Type of specimen collected, typically serum or plasma
• Date and time of specimen collection
• Method used for analysis, such as liquid chromatography–tandem mass spectrometry (LC–MS/MS)
• Quantitative result for carbamazepine –10,11–epoxide

7. Billing guidelines

When billing for CPT 80161, ensure that the test is performed to measure the level of carbamazepine –10,11–epoxide in the patient’s specimen. It is important to note that some payers may separately reimburse for the collection of the specimen using a code such as 36415. Additionally, there may be separate codes available for testing total carbamazepine or free carbamazepine, which should be reported separately if performed.

8. Historical information

CPT 80161 was added to the Current Procedural Terminology system on January 1, 2021. There have been no updates to the code since its addition.

9. Examples

1. A patient taking carbamazepine for epilepsy exhibits symptoms of possible toxic levels of carbamazepine –10,11–epoxide, and a quantitative test is performed to measure the level of the metabolite in their serum.
2. A patient with a neurological disorder is prescribed carbamazepine, and despite therapeutic levels of total carbamazepine, they show signs of potential toxicity. A quantitative test is conducted to measure the level of carbamazepine –10,11–epoxide in their plasma.
3. A psychiatric patient on carbamazepine therapy experiences symptoms suggestive of elevated levels of carbamazepine –10,11–epoxide. A quantitative test is performed to determine the level of the metabolite in their serum.
4. A patient with a history of seizures is taking carbamazepine, and their healthcare provider suspects possible toxicity. A quantitative test is ordered to measure the level of carbamazepine –10,11–epoxide in their plasma.
5. A patient on carbamazepine therapy for a neurological disorder shows signs of potential toxicity. A quantitative test is conducted to measure the level of carbamazepine –10,11–epoxide in their serum.
6. A psychiatric patient taking carbamazepine exhibits symptoms suggestive of elevated levels of carbamazepine –10,11–epoxide. A quantitative test is performed to determine the level of the metabolite in their plasma.
7. A patient with epilepsy is prescribed carbamazepine and experiences symptoms that may indicate toxicity. A quantitative test is ordered to measure the level of carbamazepine –10,11–epoxide in their serum.
8. A neurological disorder patient on carbamazepine therapy shows signs of potential toxicity. A quantitative test is conducted to measure the level of carbamazepine –10,11–epoxide in their plasma.
9. A psychiatric patient taking carbamazepine exhibits symptoms suggestive of elevated levels of carbamazepine –10,11–epoxide. A quantitative test is performed to determine the level of the metabolite in their serum.