Today, my dad was told by a doctor that he's a hepatitis b carrier. previously, we all were told by multiple docs that he just had immunity to it. don't have detailed blood test results yet. do we need a second opinion? should we all get tested?

The only way to know if he is a carrier or immune, from a vaccine, for example, is to see the results of the blood tests. If the blood tests simply shows immunity, the rest of you would not need testing. If a carrier, you may want to be tested but it depends on the blood test results. There are liver specialists who can help with this diagnosis. So, see a liver specialist to make this diagnosis.

Dr Singh agreed

Yes, the question of being immune or a carrier needs to be clarified with the help of a specialist, either infectious disease or hepatologist and this can be done based on detailed results along the years. When it comes to family members there is no specific increased risk as direct transmission is not likely, check cdc.gov for reliable information.

If he has only antibody to Hepatitis B surface antigen, that indicates immunity. If he has other markers, that would indicate natural infection. To ascertain carrier status he should be tested for Hepatitis B nucleic acids and Hepatitis E antigen. Please note that in almost all cases chronic hepatitis B is curable.