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Cytomegalovirus (CMV) IgG Antibody, Serum

Published: August 9, 2026Updated: August 16, 2026

This test measures the presence of antibodies to the cytomegalovirus (CMV), a common virus that can affect nearly everyone at some point in their lives. Antibodies indicate your immune system has recognized and fought off the virus in the past.

Quick summary

["This test helps determine if you’ve had CMV infection, which can be important for monitoring immune health or planning pregnancy."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
32791-6
Short code
CMV IgG 1:2 SerPl IA-Rto
Synonyms
CMV IgG 1:2 SerPl IA-Rto
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Does This Test Measure?

The CMV IgG antibody test detects specific proteins (antibodies) your immune system produces in response to past exposure to the CMV virus. These antibodies stay in your blood for a long time after the infection has cleared, so this test can help track immunity rather than recent infection.

Why Might You Need This Test?

Doctors may order this test if you have a weakened immune system (e.g., due to HIV, chemotherapy, or organ transplant), if you’re planning pregnancy, or if you’ve had recent exposure to CMV. It can also help monitor long-term immunity in people with chronic conditions.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test is quick and typically done in a lab setting.

What Are the Results Typically Used For?

Positive results (detecting antibodies) suggest you’ve had CMV before and your immune system has developed protection. Negative results mean you either haven’t been exposed or the test was taken too soon after exposure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High CMV IgG levels are useful for assessing immunity status, especially in high-risk groups. For example, pregnant women with positive results may have lower risk of passing CMV to their baby. In immunocompromised individuals, monitoring CMV IgG can help guide preventive measures or treatment decisions.

Short name

CMV IgG Antibody

Frequently asked questions

Why was this test ordered for me?
Your doctor may have ordered it to check if you’ve had CMV, especially if you’re pregnant, have a weakened immune system, or are being monitored for long-term health. It helps prevent complications in certain situations.
What do my results mean?
A positive result means your body has antibodies against CMV, indicating past exposure. A negative result means you either haven’t been exposed or the test wasn’t done soon enough after exposure. Your doctor will discuss these findings with you.
Does this test show if I have an active CMV infection?
No, this test only shows if you’ve had CMV in the past. For active infection, your doctor might order a separate test (like CMV IgM or viral load) to check for recent infection.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy