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Official Description

Antibody; cytomegalovirus (CMV), IgM

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 86645 refers to the laboratory test for the detection of antibodies to cytomegalovirus (CMV), specifically the immunoglobulin M (IgM) type. CMV is a member of the herpes virus family and is known to be transmitted through direct contact with infected body fluids, which can include saliva, urine, breast milk, and sexual contact. In healthy adults, CMV infection may present with symptoms similar to those of mononucleosis, such as fatigue, fever, and sore throat. However, the implications of CMV infection can be more severe in certain populations. For instance, if a mother contracts CMV during pregnancy, there is a risk of birth defects in the newborn, which can lead to long-term health issues. Additionally, individuals with weakened immune systems, such as those living with acquired immune deficiency syndrome (AIDS) or patients undergoing treatment for malignancies, are at an increased risk for serious complications associated with CMV. These complications can include chorioretinitis, gastrointestinal disorders, pneumonitis, and central nervous system diseases. The testing for IgM antibodies, as indicated by CPT® Code 86645, is crucial as it helps to identify recent or current infections, which is essential for timely diagnosis and management of the disease. The IgM antibodies are typically detected using the enzyme-linked immunosorbent assay (ELISA) method, which is a common laboratory technique for measuring the presence of specific antibodies in the blood.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The test coded as CPT® 86645 is indicated for the detection of immunoglobulin M (IgM) antibodies to cytomegalovirus (CMV) in patients who may be experiencing symptoms or conditions associated with CMV infection. The following are specific indications for performing this test:

  • Recent Infection Suspected The test is performed when there is a clinical suspicion of a recent or current CMV infection, particularly in patients presenting with symptoms resembling mononucleosis.
  • Pregnancy Pregnant women may be tested for CMV IgM antibodies to assess the risk of congenital infection, which can lead to birth defects in the newborn.
  • Immunocompromised Patients Individuals with compromised immune systems, such as those with AIDS or undergoing cancer treatment, may be tested to evaluate the risk of severe CMV-related complications.

2. Procedure

The procedure for testing IgM antibodies to cytomegalovirus (CMV) involves several key steps, which are outlined below:

  • Step 1: Sample Collection A blood sample is collected from the patient, typically via venipuncture. This sample will be used for the subsequent laboratory analysis to detect the presence of CMV IgM antibodies.
  • Step 2: Laboratory Processing The collected blood sample is processed in a laboratory setting. The serum is separated from the blood cells, which is necessary for the detection of antibodies.
  • Step 3: Antibody Detection The laboratory utilizes the enzyme-linked immunosorbent assay (ELISA) method to test the serum for the presence of IgM antibodies specific to CMV. This method involves adding specific antigens to the serum sample, which will bind to any CMV IgM antibodies present.
  • Step 4: Result Interpretation After the ELISA procedure, the results are analyzed. A positive result indicates the presence of IgM antibodies, suggesting a recent or current CMV infection, while a negative result indicates the absence of these antibodies.

3. Post-Procedure

After the procedure, the patient may be advised to wait for the laboratory results, which typically take a few days. If the test result is positive for CMV IgM antibodies, further clinical evaluation and management may be necessary, especially for pregnant women or immunocompromised individuals. It is important for healthcare providers to discuss the implications of the test results with the patient, including potential follow-up testing or treatment options. Additionally, patients should be informed about the signs and symptoms of CMV infection to monitor their health effectively.

Short Descr CMV ANTIBODY IGM
Medium Descr ANTIBODY CYTOMEGALOVIRUS CMV IGM
Long Descr Antibody; cytomegalovirus (CMV), IgM
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 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.
Q4 Service for ordering/referring physician qualifies as a service exemption
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.
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
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
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
GZ Item or service expected to be denied as not reasonable and necessary
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Date
Action
Notes
2011-01-01 Changed Short description changed.
1993-01-01 Added First appearance in code book in 1993.
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Description
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