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Official Description

Neutralizing antibody, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease [COVID-19]); titer

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86409 refers to a laboratory test that measures the presence and activity of neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease (COVID-19). This test is particularly significant in evaluating a person's immune response following infection with the virus or after vaccination. It is commonly utilized to assess the eligibility of plasma donors who have recovered from COVID-19, as their plasma may contain antibodies that can be beneficial for treating patients currently infected with the virus. The neutralizing antibody test specifically quantifies the ability of these antibodies to inhibit the virus's ability to infect cells, providing insight into the level of protection an individual may have against future infections or reinfections. The process involves mixing blood serum or plasma with target cells and a synthetic virus that expresses the spike protein of SARS-CoV-2. By performing serial dilutions and measuring the luminescent signal generated in response to viral infection, healthcare professionals can determine the titer, or concentration, of neutralizing antibodies present in the sample. This information is crucial for understanding an individual's immune status and potential protection against COVID-19.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The neutralizing antibody test (CPT® Code 86409) is indicated for several specific purposes related to the assessment of immune response to SARS-CoV-2. These indications include:

  • Plasma Donor Eligibility This test is performed to evaluate whether individuals who have recovered from COVID-19 possess sufficient neutralizing antibodies in their plasma to be considered eligible donors for convalescent plasma therapy.
  • Immune Response Assessment The test is utilized to determine an individual's immune response to SARS-CoV-2, either following natural infection or vaccination, helping to ascertain the level of protection against future infections.
  • Protection Evaluation It aids in assessing whether a person is protected from reinfection by measuring the effectiveness of their neutralizing antibodies in preventing viral infection.

2. Procedure

The procedure for conducting the neutralizing antibody test involves several critical steps to ensure accurate measurement of antibody activity. These steps include:

  • Sample Collection Blood serum or plasma is collected from the patient, which serves as the sample for the test. This sample contains the antibodies that will be analyzed for their neutralizing capabilities against SARS-CoV-2.
  • Mixing with Target Cells The collected serum or plasma is then mixed with target cells that are susceptible to infection by the SARS-CoV-2 virus. This step is crucial as it sets the stage for evaluating the interaction between the antibodies and the virus.
  • Incorporation of Synthetic Virus A synthetic virus expressing the spike protein of SARS-CoV-2 is introduced into the mixture. This allows for the assessment of how well the antibodies can neutralize the virus and prevent it from infecting the target cells.
  • Serial Dilutions The mixture undergoes serial dilutions to determine the concentration of antibodies present. This step is essential for quantifying the neutralizing activity of the antibodies in a controlled manner.
  • Incubation The samples are incubated to allow sufficient time for any potential viral infection to occur, depending on the presence of neutralizing antibodies. This incubation period is critical for accurate results.
  • Substrate Addition After incubation, a substrate is added that produces a luminescent signal in the presence of viral infection. This luminescence indicates whether the virus has successfully infected the target cells.
  • Measurement and Interpretation The luminescent signal activity is measured and compared to a control specimen. The results are interpreted to determine the titer of neutralizing antibodies, providing insight into the effectiveness of the immune response.

3. Post-Procedure

Post-procedure care for patients undergoing the neutralizing antibody test is generally minimal, as the test primarily involves laboratory analysis of blood samples. However, it is important to monitor patients for any potential adverse reactions related to blood collection, such as bruising or discomfort at the venipuncture site. Results from the test may take some time to process, and healthcare providers should communicate the findings to the patient, discussing the implications of the antibody titer in relation to their immune status and potential protection against COVID-19. Follow-up consultations may be necessary to address any questions or concerns regarding the results and subsequent health decisions.

Short Descr NEUTRLZG ANTB SARSCOV2 TITER
Medium Descr NEUTRALIZING ANTIBODY SARS-COV-2 TITER
Long Descr Neutralizing antibody, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease [COVID-19]); titer
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 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.
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.
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
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
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
2023-01-01 Note Grammar correction
2022-01-01 Added First appearance in code book
2022-01-01 Changed Code description changed.
2021-01-01 Added First appearance of code in CPT® Code Set.
2020-08-10 Added Code added.
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Description
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