Abstract: Purpose: This article describes the implementation and evaluation of pharmacogenomic testing within the hematology/oncology ambulatory care clinic at the William S. Middleton Memorial Veterans Hospital in Madison, WI. Summary: The Pharmacogenomic Testing for Veterans (PHASER) program provides preemptive pharmacogenomic testing for veterans nationally. Program implementation at the Madison Veterans Affairs site began in the hematology/oncology clinic with the goal of integrating the offer for pharmacogenomic testing, testing completion, and review of the results by the hematology/oncology clinical pharmacist practitioner (CPP) into current workflows to create a sustainable process for PHASER. The hematology/oncology CPP designed workflows outlining how testing would be offered to patients, how results would be reported and to whom, and how documentation would occur in the electronic medical record. Veterans are offered preemptive PHASER testing, before needing therapy requiring pharmacogenomic results. Exceptions to pharmacogenomic testing were patients with a history of liver or allogeneic hematopoietic stem cell transplantation. Conclusion: This article provides a summary of the role of the hematology/oncology CPP in the implementation of a pharmacogenomics service and the impact on medication management in a hematology/oncology clinic.