This study investigates how pharmacists dispense generic drugs by considering patients' brand preferences. While the literature shows that pharmacists, as experts, underestimate brand premiums, our data show that they frequently dispense brandidentical generics, known as authorized generics. We model patients' generic drug choices and pharmacies' dispensing decisions to explain how patients' brand preferences vary across pharmacies and to determine for-profit pharmacists' heterogeneous dispensing behavior. Using Japanese pharmacists' dispensing data, our empirical results show significant variations in patients' brand preferences and perceived differences in the quality of antibiotics. Furthermore, our findings show that one of the factors behind these differences is the provision of information by pharmacists.