SBHC users less likely than other users to be insured (37% vs. 73%), more likely to have made three or more primary care visits (52% vs. 34%), less likely to have used emergency care (17% vs. 34%), more likely to have received a health maintenance visit (47% vs. 33%), influenza vaccine (45% vs. 18%), a tetanus booster (33% vs. 21%), and a hepatitis B vaccine (46% vs. 20%). Compared to traditional outpatient sites, SBHCs improve access to care for underserved adolescents. This evidence concerns the gene PPIB and hepatitis A virus infection.