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Official Description

Antibody; virus, not elsewhere specified

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86790 refers to a laboratory test specifically designed to identify and measure antibodies against viruses that are not categorized elsewhere in the coding system. This test is crucial for diagnosing infections caused by various viruses, as it helps in determining the immune response of an individual to these pathogens. The procedure involves obtaining a blood sample, typically through a process known as venipuncture, which is a standard method for collecting blood for laboratory analysis. Once the blood sample is collected, the serum or plasma is subjected to testing methodologies such as enzyme-linked immunosorbent assay (ELISA), immunoassay (IA), or complement fixation. These techniques are employed to detect the presence of antibodies that indicate exposure to specific viruses. The code 86790 encompasses testing for a range of viruses, including but not limited to human T-lymphotropic virus (HTLV), dengue fever virus, rabies, hantavirus, Japanese encephalitis, hepatitis E virus (HEV), herpesvirus 6, chikungunya virus, parainfluenza virus, and zika virus. This broad spectrum of testing underscores the importance of the code in the context of viral diagnostics, allowing healthcare providers to assess and manage viral infections effectively.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The CPT® Code 86790 is indicated for use in various clinical scenarios where there is a need to identify and measure antibodies to specific viruses that are not classified under other codes. The following conditions may warrant the use of this test:

  • Human T-lymphotropic virus (HTLV) Testing for antibodies to HTLV is essential in diagnosing infections that can lead to conditions such as adult T-cell leukemia and tropical spastic paraparesis.
  • Dengue fever virus This test is indicated for patients presenting with symptoms consistent with dengue fever, particularly in endemic regions.
  • Rabies Antibody testing for rabies is crucial for assessing post-exposure prophylaxis effectiveness and for diagnosing suspected rabies infections.
  • Hantavirus Testing for hantavirus antibodies is indicated in cases of suspected hantavirus pulmonary syndrome, especially in patients with a history of exposure to rodent habitats.
  • Japanese encephalitis This test is performed for patients exhibiting neurological symptoms in areas where Japanese encephalitis is endemic.
  • Hepatitis E virus (HEV) Testing for HEV antibodies is important in diagnosing hepatitis E, particularly in pregnant women and individuals with liver disease.
  • Herpesvirus 6 This test is indicated for patients with symptoms of roseola or other herpesvirus-related illnesses.
  • Chikungunya virus Testing for chikungunya antibodies is essential for diagnosing this viral infection, especially in patients with fever and joint pain following travel to endemic areas.
  • Parainfluenza virus This test is indicated for patients with respiratory symptoms, particularly in pediatric populations.
  • Zika virus Testing for Zika virus antibodies is crucial for pregnant women or individuals with symptoms following travel to areas with Zika virus transmission.

2. Procedure

The procedure for CPT® Code 86790 involves several key steps to ensure accurate testing for antibodies against the specified viruses. The first step is the collection of a blood sample from the patient, which is typically performed through venipuncture. This method involves inserting a needle into a vein, usually in the arm, to draw blood into a sterile collection tube. Once the blood is collected, it is processed to separate the serum or plasma, which is the component that will be tested for antibodies.

Following the collection and processing of the blood sample, the serum or plasma is subjected to laboratory testing using one of several methodologies. The enzyme-linked immunosorbent assay (ELISA) is a common technique used to detect the presence of specific antibodies in the sample. This method involves coating a plate with viral antigens, adding the serum or plasma, and then using enzyme-linked antibodies to produce a measurable signal if antibodies are present. Alternatively, an immunoassay (IA) may be employed, which utilizes similar principles but may vary in the detection mechanism. Complement fixation is another method that can be used, where the presence of antibodies is determined by their ability to fix complement in the presence of specific antigens.

Each of these testing methods is designed to provide reliable results regarding the presence of antibodies to the specified viruses, allowing healthcare providers to make informed decisions regarding diagnosis and treatment.

3. Post-Procedure

After the procedure associated with CPT® Code 86790, the patient may be advised to resume normal activities unless otherwise directed by their healthcare provider. The laboratory will analyze the blood sample and report the results, which typically include the presence or absence of antibodies to the specified viruses. Depending on the results, further clinical evaluation or additional testing may be necessary. It is important for healthcare providers to discuss the results with the patient, including any implications for treatment or further diagnostic steps. Additionally, patients should be informed about any potential follow-up appointments or additional tests that may be required based on their individual health status and the results of the antibody testing.

Short Descr VIRUS ANTIBODY NOS
Medium Descr ANTIBODY VIRUS NOT ELSEWHERE SPECIFIFED
Long Descr Antibody; virus, not elsewhere specified
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 Conditionally packaged laboratory tests
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) T1H - Lab tests - other (non-Medicare fee schedule)
MUE 4
CCS Clinical Classification 235 - Other Laboratory
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.
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
91 Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient.
GA Waiver of liability statement issued as required by payer policy, individual case
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.
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.
GZ Item or service expected to be denied as not reasonable and necessary
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
Date
Action
Notes
1993-01-01 Added First appearance in code book in 1993.
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