How To Use CPT Code 82787

CPT 82787 describes the measurement of immunoglobulin subclasses, specifically IgG1, IgG2, IgG3, and IgG4, in a serum or spinal fluid specimen. This article will cover the official description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, similar codes and billing examples.

1. What is CPT Code 82787?

CPT 82787 can be used to measure the levels of immunoglobulin subclasses, specifically IgG1, IgG2, IgG3, and IgG4, in a serum or spinal fluid specimen. This code is used when a lab analyst performs the necessary steps to quantitate the levels of these subclasses using nephelometry, a method that measures the intensity of light scattering to determine the analyte’s quantitation.

2. Official Description

The official description of CPT code 82787 is: ‘Gammaglobulin (immunoglobulin); immunoglobulin subclasses (eg, IgG1, 2, 3, or 4), each.’

3. Procedure

1. The lab analyst performs the technical lab steps to quantitate the levels of immunoglobulin subclasses in a serum or spinal fluid specimen.
2. The method used for quantitation is nephelometry, which measures the intensity of light scattering to determine the analyte’s quantitation.
3. The lab analyst primarily focuses on measuring the immunoglobulin G (IgG) fraction, which has four subclasses: IgG1, IgG2, IgG3, and IgG4.
4. The lab analyst may also perform testing for other immunoglobulin classes, such as immunoglobulin A (IgA), which has subclasses IgA1 and IgA2.

4. Qualifying circumstances

CPT 82787 is typically ordered by clinicians to diagnose conditions such as hypogammaglobulinemia or selective IgG subclass deficiency. These conditions affect immunity to infections, and the most definitive testing involves measuring the individual subclasses. The test is not limited to a specific condition and can be used for any patient requiring measurement of immunoglobulin subclasses.

5. When to use CPT code 82787

CPT code 82787 should be used when a lab analyst performs the measurement of immunoglobulin subclasses, specifically IgG1, IgG2, IgG3, and IgG4, in a serum or spinal fluid specimen. This code is appropriate when the clinician orders the test to diagnose conditions related to hypogammaglobulinemia or selective IgG subclass deficiency.

6. Documentation requirements

To support a claim for CPT 82787, the lab analyst must document the following information:

• Patient’s diagnosis or reason for ordering the test
• Specific immunoglobulin subclasses measured (e.g., IgG1, IgG2, IgG3, IgG4)
• Date of the test
• Results of the quantitation for each subclass
• Signature of the lab analyst performing the test

7. Billing guidelines

When billing for CPT 82787, report one unit of the code for each immunoglobulin subclass ordered and tested. For example, if the lab performs quantitation for all four subclasses (IgG1, IgG2, IgG3, and IgG4), report four units of CPT 82787. It is important to note that some payers may separately reimburse for specimen collection using codes such as 36415 for venipuncture or 62270 for lumbar puncture, if the lab personnel were responsible for the collection.

8. Historical information

CPT 82787 was added to the Current Procedural Terminology system on January 1, 1993. Since then, there have been several changes to the code, including updates to the description and the addition of specific immunoglobulin subclasses.

9. Examples

1. A lab analyst measuring the levels of IgG1, IgG2, IgG3, and IgG4 in a serum specimen to diagnose a patient with hypogammaglobulinemia.
2. A clinician ordering the measurement of IgG subclasses in a spinal fluid specimen to assess a patient with selective IgG subclass deficiency.
3. A lab analyst performing the quantitation of IgG subclasses in a serum specimen to monitor the response to immunoglobulin replacement therapy in a patient with primary immunodeficiency.
4. A clinician requesting the measurement of IgG subclasses in a serum specimen to investigate recurrent infections in a pediatric patient.
5. A lab analyst measuring the levels of IgG subclasses in a spinal fluid specimen to evaluate a patient with suspected central nervous system infection.
6. A clinician ordering the quantitation of IgG subclasses in a serum specimen to assess the immune response in a patient with autoimmune disease.
7. A lab analyst performing the measurement of IgG subclasses in a serum specimen to investigate a patient with suspected allergic reactions.
8. A clinician requesting the quantitation of IgG subclasses in a spinal fluid specimen to evaluate a patient with suspected neurologic autoimmune disorder.
9. A lab analyst measuring the levels of IgG subclasses in a serum specimen to assess the immune status of a patient prior to immunosuppressive therapy.
10. A clinician ordering the measurement of IgG subclasses in a spinal fluid specimen to investigate a patient with suspected neuroinflammatory disease.