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Hepatitis B Core Antibody (IgG) – Serum

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

This test detects antibodies to the hepatitis B core antigen, which can indicate past or current hepatitis B infection. IgG antibodies typically develop after initial infection and remain in the blood long-term.

Quick summary

["Helps track hepatitis B infection status and immunity over time."]

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

Key facts at a glance

LOINC
40725-4
Short code
HBV core IgG Ser Ql IA
Synonyms
HBV core IgG Ser Ql IA
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

Why This Test Matters for Your Health

Hepatitis B is a viral infection that can affect your liver. The hepatitis B core antibody IgG test helps doctors determine if you’ve been exposed to the virus, whether you’ve recovered from infection, or if you’re immune. This information is important for managing your health, especially if you’re at higher risk for infection.

What Does a Positive Result Mean?

A positive result means you likely had hepatitis B in the past and your body produced IgG antibodies to fight it. These antibodies can stay in your system for years, providing long-term immunity. This does not mean you’re currently infected; it means your immune system has already responded to the virus.

What If My Result Is Negative?

A negative result suggests you either haven’t been exposed to hepatitis B or your body hasn’t yet produced detectable IgG antibodies. If you’re at risk for hepatitis B (e.g., due to travel, medical procedures, or occupation), follow-up testing or vaccination may be recommended.

How Is This Test Performed?

A blood sample is taken from a vein in your arm. The sample is sent to a lab where it’s tested using an immunoassay method to detect IgG antibodies to the hepatitis B core antigen.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Understanding Your Results

Short name

Hepatitis B Core Antibody IgG

Frequently asked questions

Can I get hepatitis B if my test is positive for IgG antibodies?
No, a positive IgG result indicates past infection and immunity, not current infection. However, if you’re unsure about your vaccination status or recent exposure, discuss it with your healthcare provider.
What if I’m pregnant and this test is positive?
If you’re pregnant and test positive for IgG antibodies, your healthcare provider may recommend additional testing (like hepatitis B surface antigen) to assess your risk of passing the virus to your baby. Vaccination for your baby may also be recommended.
How long do IgG antibodies last after hepatitis B infection?
IgG antibodies can remain in your system for months to years after infection, providing long-term immunity. However, their levels may gradually decrease over time, so follow-up testing may be advised if you’re at ongoing risk.
  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