Currently, adults who receive a hepatitis B vaccination typically receive a 3-dose series over 6 months. However, a large, multi-site cohort study reported only 64% of adults who began the vaccine series actually received all 3 doses and only 81% received two doses, indicating many adults who start the current vaccine series remain at risk for HBV infection. Additionally, there is evidence that older adults, diabetic persons, persons with renal disease, obese persons and smokers may have a reduced response to the ENGERIX-B or Recombivax-HB series. In 2017, the U.S. Food and Drug Administration approved the use of HEPLISAV-B, a 2-dose vaccine series that can be administered over one month. This project will determine which risk groups could most benefit from preferentially receiving the HEPLISAV-B vaccine instead of the currently administered 3-dose series.