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Official Description

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease [COVID-19]) antibody, quantitative

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86413 refers to a quantitative test for antibodies against the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which is responsible for the disease known as COVID-19. This test is crucial for understanding the immune response to the virus, as it measures the level of antibodies produced either through natural infection or vaccination. Antibodies play a significant role in providing protection against COVID-19, but their levels can vary widely among individuals and may diminish over time. The quantitative nature of this test allows healthcare providers to assess not only the presence of antibodies but also their concentration, which can indicate the degree of protection an individual may have against the virus. The test employs a solid phase immunoassay methodology, specifically designed to detect antibodies that bind to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. This process involves immobilizing the RBD on a solid support, which serves as the antigen in the assay. A blood sample is collected from the patient, and the serum is then mixed with the immobilized RBD. Following incubation, anti-human antibodies are introduced to bind to any human anti-RBD antibodies present in the sample. After washing away any nonreactive substances, the concentration of the anti-RBD antibodies is determined using a standard calibration curve, and the results are reported in quantitative units. This information is not only vital for individual patient care but also contributes to broader research efforts aimed at understanding vaccine efficacy, the duration of immunity, and the need for booster vaccinations.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The quantitative antibody test for SARS-CoV-2 (CPT® Code 86413) is indicated for several specific purposes related to the assessment of immune response to COVID-19. These indications include:

  • Assessment of Immune Response: To evaluate the level of antibodies produced in response to a previous infection with SARS-CoV-2 or following vaccination against COVID-19.
  • Monitoring Immunity: To monitor the duration and strength of immunity over time, particularly in individuals who have been vaccinated or previously infected.
  • Research Purposes: To provide data for research studies aimed at understanding the effectiveness of different vaccines and the longevity of immune protection against COVID-19.

2. Procedure

The procedure for conducting the quantitative antibody test for SARS-CoV-2 involves several detailed steps, which are as follows:

  • Step 1: Sample Collection A blood sample is collected from the patient, typically via venipuncture. This sample is essential for obtaining the serum needed for the test.
  • Step 2: Serum Preparation The collected blood sample is processed to separate the serum, which contains the antibodies. This is done by allowing the blood to clot and then centrifuging it to separate the liquid serum from the cellular components.
  • Step 3: Incubation with Antigen The prepared serum is then added to a solution containing the immobilized receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. This mixture is incubated to allow any anti-RBD antibodies present in the serum to bind to the immobilized antigen.
  • Step 4: Addition of Detection Antibodies After incubation, anti-human antibodies are introduced to the mixture. These antibodies are designed to bind specifically to the human anti-RBD antibodies that have attached to the immobilized antigen.
  • Step 5: Washing The sample undergoes a washing step to remove any unbound or nonreactive substances, ensuring that only the specific antibody-antigen complexes remain for analysis.
  • Step 6: Quantification The concentration of the bound anti-RBD antibodies is then calculated using a standard calibration curve. This quantification is reported in specific quantitative units, providing a measure of the antibody level in the patient's serum.

3. Post-Procedure

After the quantitative antibody test for SARS-CoV-2 is completed, the results are typically reviewed and interpreted by a healthcare professional. Patients may not require any specific post-procedure care, as the test involves a standard blood draw. However, it is important for healthcare providers to communicate the results to the patient, discussing the implications of the antibody levels in relation to their immune response to COVID-19. Additionally, the results may inform decisions regarding vaccination strategies, including the need for booster shots, based on the level of immunity indicated by the test.

Short Descr SARS-COV-2 ANTB QUANTITATIVE
Medium Descr SEV AQT RESPIR SYND CORONAVIRUS 2 ANTIBODY QUAN
Long Descr Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease [COVID-19]) antibody, quantitative
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 Service Paid under Fee Schedule or Payment System other than OPPS
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) none
MUE 3
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.
GW Service not related to the hospice patient's terminal condition
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
Action
Notes
2022-01-01 Added First appearance in code book
2022-01-01 Note Grammar correction
2021-01-01 Added First appearance of code in CPT® Code Set.
2020-09-08 Added Code added.
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Description
Code
Description
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