Cytomegalovirus (CMV) Antibodies
Cytomegalovirus antibody testing detects IgG and IgM antibodies to determine past or current CMV infection status, particularly important for pregnant individuals and those with weakened immune systems.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
This test detects antibodies to cytomegalovirus (CMV), a member of the herpes virus family that is widespread enough that the majority of adults have been infected by midlife. Like other herpes-family viruses, CMV establishes a lifelong latent infection after the initial exposure and can reactivate periodically, particularly during periods of immune suppression. The virus spreads through contact with bodily fluids including saliva, blood, urine, breast milk, and semen.
The test measures two antibody classes: IgM antibodies, which appear first during a new or reactivated infection, and IgG antibodies, which develop later and typically persist for life after exposure. Most healthy individuals experience no symptoms during CMV infection and may never realize they have been exposed. The clinical significance of CMV testing is greatest for pregnant individuals (since primary CMV infection during pregnancy can affect the developing fetus), organ transplant recipients, and immunocompromised individuals, all of whom face elevated risk of complications from active CMV infection.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Women who are pregnant or planning to become pregnant may benefit from CMV testing, as primary infection during pregnancy can potentially transmit the virus to the developing baby.
- Individuals with weakened immune systems, including those with HIV/AIDS, organ transplant recipients, or cancer patients receiving chemotherapy, should consider testing since CMV can cause serious complications in immunocompromised individuals.
- Healthcare workers and childcare providers who have frequent contact with bodily fluids may want to know their CMV status for occupational health purposes.
- Those experiencing unexplained flu-like symptoms, prolonged fatigue, or mononucleosis-like symptoms may consider testing to rule out active CMV infection.
- Blood or organ donors may need CMV testing to determine their infection status, as this information is important for recipient safety.
- Individuals with partners who are pregnant or immunocompromised may want to know their CMV status to understand transmission risks.
What to expect
Preparation
No special preparation is needed for this test. No fasting is required, and individuals can eat and drink normally before the blood draw.
Sample Type
A healthcare professional will take a blood sample from a vein in the arm using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial.
Collection
The blood draw is performed at a lab location and typically takes just a few minutes. Patients may experience brief discomfort when the needle is inserted, but the process is generally quick and straightforward.
Turnaround
Results are typically available within 1-3 business days after the lab receives the sample. The lab will measure both IgG and IgM antibody levels to determine infection status.
Understanding your results
Results are reported separately for IgM and IgG antibodies. A negative result for both indicates no detectable prior exposure to CMV. A positive IgG with negative IgM suggests past infection with established immunity and no evidence of current active infection. A positive IgM (with or without IgG) may indicate a new or recently reactivated infection, though IgM can occasionally persist for months after the initial infection, complicating the timeline. Healthcare providers interpret the antibody pattern alongside clinical symptoms, immune status, and the specific clinical question being asked (such as pregnancy screening or transplant evaluation) to determine the significance of the findings.
| Population | Reference Range | Notes |
|---|---|---|
| Adults - CMV IgG | Negative: <0.6 U/mL, Equivocal: 0.6-0.69 U/mL, Positive: ≥0.7 U/mL | Positive IgG indicates past or current CMV infection with lifelong immunity |
| Adults - CMV IgM | Negative: <30 AU/mL, Equivocal: 30-34.9 AU/mL, Positive: ≥35.0 AU/mL | Positive IgM may indicate recent infection or reactivation |
Reference ranges may vary by laboratory and individual factors. Results should be interpreted by a healthcare provider in the context of your overall health.
What does a “Low” result mean?
Individuals with negative CMV IgG results are presumed to not have had prior exposure or infection with CMV and are considered susceptible to primary infection. Negative or low IgG and/or IgM levels may mean that symptoms are due to an infection other than CMV or possibly that the immune system is not responding normally. In immunocompromised individuals, low antibody levels may occur even during active infection due to impaired immune response.
What does a “High” result mean?
Positive CMV IgG results indicate past or recent CMV infection. Once exposed to CMV, individuals will have some measurable amount of CMV IgG antibody in blood for the rest of their life, which provides protection from getting another primary infection. Positive CMV IgM results indicate a recent infection (primary, reactivation, or reinfection). High levels of both IgG and IgM antibodies together may suggest an active infection, and healthcare providers often recommend repeat testing in 2-3 weeks to monitor changes in antibody levels.
Privacy & confidentiality
CMV antibody test results are completely confidential and HIPAA-protected. Results are not shared with insurance companies, added to medical records without your consent, or reported to employers. No doctor visit is required to order this confidential screening.
Frequently asked questions
Related tests
Mononucleosis Test
CMV can cause mononucleosis-like symptoms and may be tested alongside EBV
View TestHerpes Simplex Virus Test
CMV is part of the herpes virus family and may be tested with other herpes viruses
View TestHIV Test
HIV patients are at higher risk for CMV complications and often need CMV monitoring
View TestComplete Blood Count (CBC)
CBC may show characteristic changes during CMV infection such as lymphocytosis
View TestLast reviewed: April 2026
CPT Code: 86644, 86645
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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