The purpose of this clinical research study is to assess the pharmacokinetics of atazanavir, identifying one or more dosing regimens of atazanavir/ritonavir/tenofovir when dosed with famotidine results in atazanavir exposures similar to those when atazanavir/ritonavir/tenofovir 300/100/300 mg is dosed without famotidine in healthy subjects.