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Official Description

Infectious agent antigen detection by immunoassay technique, (eg, enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], fluorescence immunoassay [FIA], immunochemiluminometric assay [IMCA]) qualitative or semiquantitative; rotavirus

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 87425 refers to a laboratory test specifically designed for the detection of rotavirus antigen using various immunoassay techniques. Rotavirus is a group of viruses characterized by their wheel-like shape, primarily affecting the intestines and leading to rotaviral enteritis, which is most prevalent in infants and young children. This condition is marked by severe diarrhea, often resulting in copious amounts of watery stool, which can lead to dehydration, abdominal cramps, anorexia, low-grade fever, vomiting, and significantly decreased urine output, along with the loss of essential electrolytes. The test involves obtaining a fecal sample, which can either be placed in a fixative or sent fresh to the laboratory for analysis. The detection methods included in this code encompass enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), fluorescence immunoassay (FIA), and immunochemiluminometric assay (IMCA). EIA and ELISA are particularly sensitive techniques that can identify very small quantities of the rotavirus antigen by utilizing a specific antibody that binds to the antigen in the sample. A secondary enzyme-labeled antibody is then added, which facilitates the detection of the antigen through a chromogenic reaction, resulting in a visible color change or fluorescence that can be quantitatively assessed. FIA operates on a similar principle but employs a fluorescent compound to detect the binding of the antibody to the analyte molecule, allowing for the measurement of fluorescence at different wavelengths. IMCA, on the other hand, utilizes antibodies labeled with a chemiluminescent substance to identify and quantify the antigen-antibody complex through light emission. The results of this test can be reported qualitatively or semi-quantitatively, providing crucial information for the diagnosis and management of rotavirus infections.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The CPT® Code 87425 is indicated for the detection of rotavirus antigen in patients who present with symptoms consistent with rotaviral enteritis. The following conditions may warrant the use of this test:

  • Severe Diarrhea The presence of copious watery stools, particularly in infants and young children, which may lead to dehydration.
  • Abdominal Cramps Patients may experience significant abdominal discomfort associated with gastrointestinal distress.
  • Anorexia A noticeable decrease in appetite, often accompanying gastrointestinal infections.
  • Low-Grade Fever Mild fever that may occur as part of the body's response to infection.
  • Vomiting Episodes of vomiting that can accompany diarrhea and contribute to dehydration.
  • Decreased Urine Output A reduction in urine production, which can be a sign of dehydration due to fluid loss from diarrhea.
  • Electrolyte Loss Symptoms related to the loss of electrolytes, which can occur with severe diarrhea and vomiting.

2. Procedure

The procedure for conducting the test under CPT® Code 87425 involves several key steps to ensure accurate detection of the rotavirus antigen:

  • Sample Collection A fecal sample is collected from the patient, which is critical for the subsequent analysis. The sample can either be placed in a fixative to preserve its integrity or sent fresh to the laboratory for processing.
  • Preparation of the Sample Once the sample reaches the laboratory, it is prepared for testing. This may involve homogenizing the fecal matter to ensure that the antigen is evenly distributed within the sample.
  • Immunoassay Technique Selection The laboratory technician selects an appropriate immunoassay technique for the detection of the rotavirus antigen. This could be EIA, ELISA, FIA, or IMCA, depending on the laboratory's capabilities and protocols.
  • Antigen Detection The chosen immunoassay technique is employed to detect the presence of the rotavirus antigen. For EIA and ELISA, a specific antibody is added to the sample, followed by a secondary enzyme-labeled antibody that binds to the antigen. A chromogenic reaction occurs, resulting in a color change that indicates the presence of the antigen.
  • Fluorescence Measurement In the case of FIA, a fluorescent compound is used to detect the binding of the detection antibody to the rotavirus antigen. The fluorescence emitted is measured to determine the presence and quantity of the antigen.
  • Chemiluminescent Detection For IMCA, antibodies labeled with a chemiluminescent substance are used to identify the antigen-antibody complex. The light emitted during the reaction is measured to quantify the antigen present in the sample.
  • Result Interpretation The results of the test are assessed qualitatively or semi-quantitatively based on the colorimetric readings or fluorescence measurements, providing valuable information for diagnosing rotavirus infections.

3. Post-Procedure

After the completion of the test, the laboratory will analyze the results and report them to the requesting physician. It is essential for healthcare providers to interpret the results in conjunction with the patient's clinical presentation and history. If the test indicates the presence of rotavirus antigen, appropriate management strategies should be implemented to address the infection and prevent complications such as dehydration. Follow-up care may include monitoring the patient's hydration status, electrolyte levels, and overall clinical condition. In cases of severe dehydration, further medical intervention may be necessary, including intravenous fluid administration. Additionally, healthcare providers should educate caregivers on the signs of dehydration and the importance of maintaining fluid intake during the recovery process.

Short Descr ROTAVIRUS AG IA
Medium Descr IAAD IA ROTAVIRUS
Long Descr Infectious agent antigen detection by immunoassay technique (eg, enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], fluorescence immunoassay [FIA], immunochemiluminometric assay [IMCA]), qualitative or semiquantitative; rotavirus
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 1
CCS Clinical Classification 206 - Microscopic examination (bacterial smear, culture, toxicology)
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.
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.
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.
GW Service not related to the hospice patient's terminal condition
Q4 Service for ordering/referring physician qualifies as a service exemption
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
Date
Action
Notes
2022-01-01 Changed First appearance of change in codebook.
2022-01-01 Note Grammatical correction.
2021-01-01 Changed First appearance of change in CPT® Code Set.
2020-10-06 Changed Code description changed.
2016-01-01 Changed Description Changed
2011-01-01 Changed Short description changed.
2007-01-01 Changed Code description changed.
1998-01-01 Added First appearance in code book in 1998.
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Description
Code
Description
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