Hepatitis B Titer Test — Surface Antibody Quantitative
Immunity Titer Guide
Content last reviewed 2026-09-12 · Educational information — not medical advice
Quick answer
Quantifies anti-HBs antibody; ≥10 mIU/mL counts as immune for compliance. The most commonly FAILED titer — 5–10% of people never respond to the standard vaccine series, triggering revaccination pathways.
Who this covers
Why quantitative matters
Qualitative 'reactive' reports don't satisfy most healthcare compliance — the NUMBER decides, and borderline values (10–50) wane faster than robust ones (>100).
The non-responder ladder
First series failed → second full series (sometimes higher-dose/adjuvanted) → re-titer. Still under 10? Documented antigen-negative status plus risk counseling becomes the endpoint — permanent 'non-responder' designation.
Timing trap
Test 1–2 MONTHS after your final vaccine dose, not days later — early draws undercount the developing response.
Order the required tests
Direct-access laboratory testing — no doctor visit needed. Results arrive as forwardable PDFs that satisfy most compliance offices.
We may earn a commission when you order through partner links. This guide is educational and never replaces advice from your program office, employer, or healthcare provider.
Related guides
Frequently asked questions
My titer was 8 mIU/mL — am I exposed?
Below-threshold means insufficient DOCUMENTED protection — one booster dose then re-titer frequently crosses 100+. Genuine susceptibility after full re-vaccination has its own documented-management pathway.
Do I need this if my employer accepted vaccine cards?
Clinical contracts increasingly don't. Quantitative titers end the argument — bring numbers, not photocopies.