What does the medical abbreviation HBs Ag Non-reactive mean?

You do not have Hepatitis Surface B antigens present. This can mean you do not have Hep B or if you have had vaccinations and are getting tested within months of the shots, they have not produced sufficient immunity. (If the titer is done years after the immunization, the levels may be non-reactive, but the body still may produce an anamnestic response demonstrating that low titer levels years after immunization are not an effective indicator of immune status.)