How To Use CPT Code 85421

CPT 85421 describes the measurement of fibrinolytic plasminogen levels using an immunoassay. 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 85421?

CPT 85421 can be used to measure the levels of fibrinolytic plasminogen in a patient’s serum using an immunoassay method. This test helps evaluate the patient’s ability to break down fibrin, which is crucial for controlling blood clot formation and dissolution.

2. Official Description

The official description of CPT code 85421 is: ‘Fibrinolytic factors and inhibitors; plasminogen, antigenic assay.’

3. Procedure

1. The lab analyst performs the technical steps to evaluate plasminogen levels in the patient’s serum using an immunoassay method.
2. The lab method involves mixing the patient’s serum with a labeled antibody that binds to specific antigens on the plasminogen molecule in the patient’s plasma.
3. The lab analyst then evaluates the concentration of the antibody using a fluorescent or other marker.

4. Qualifying circumstances

CPT 85421 may be ordered by clinicians to differentiate between quantitative deficiency and functional deficiency of plasminogen. Quantitative deficiency shows equally decreased plasminogen antigen and activity levels, indicating a reduced amount of plasminogen. Functional deficiency, on the other hand, shows reduced plasminogen activity with normal plasminogen antigen, indicating dysfunctional plasminogen. This test is not limited to specific conditions and can be ordered based on clinical judgment.

5. When to use CPT code 85421

CPT code 85421 should be used when measuring fibrinolytic plasminogen levels using an immunoassay method. It is appropriate when there is a need to evaluate the patient’s ability to break down fibrin and determine the presence of plasminogen deficiency. This code should not be used for tests assessing plasminogen activity using other lab methods.

6. Documentation requirements

To support a claim for CPT 85421, the documentation should include:

• Reason for ordering the test
• Details of the immunoassay method used
• Date and time of the test
• Results of the plasminogen antigenic assay
• Signature of the lab analyst performing the test

7. Billing guidelines

When billing for CPT 85421, ensure that the test is performed using an immunoassay method to measure fibrinolytic plasminogen levels. It is important to distinguish this test from other lab methods assessing plasminogen activity. Additionally, some payers may separately reimburse for specimen collection using a venipuncture code such as 36415.

8. Historical information

CPT 85421 was added to the Current Procedural Terminology system on January 1, 1990. There have been no updates to the code since its addition.

9. Examples

1. A lab analyst performs an immunoassay to measure fibrinolytic plasminogen levels in a patient’s serum to assess their ability to break down fibrin.
2. A clinician orders CPT 85421 to differentiate between quantitative and functional deficiency of plasminogen in a patient with suspected fibrinolysis-related issues.
3. A patient undergoes an immunoassay to evaluate their plasminogen levels as part of a comprehensive coagulation profile.
4. A lab technician performs an immunoassay to measure fibrinolytic plasminogen levels in a patient’s serum to monitor the effectiveness of a fibrinolysis-related treatment.
5. A clinician orders CPT 85421 to assess the plasminogen levels in a patient with a history of thromboembolisms.