Since 2011, Dr. Pfeiffer has served as the Hospital Epidemiologist at the VA Portland Health Care System (VAPORHCS) and as an Infectious Diseases (ID) physician, rounding on both General and Transplant ID consult services at VAPORHCS and Oregon Health & Science University (OHSU).   Since 2018, he also serves as the Chief for the VAPORHCS ID section.

In 2012, he began what is a fruitful ongoing collaboration with the Oregon Health Authority (OHA) by becoming the Medical Director for our Drug-Resistant Organism Prevention and Coordinated Regional Epidemiology (DROP-CRE) Network. The primary goals of DROP-CRE Network, which is funded through OHA by CDC, are to prevent, detect, and control the spread of multidrug-resistant organisms (MDROs) with a focus on carbapenem-resistant Enterobacteriaceae (CRE) and more recently C. auris in Oregon. 

Dr. Pfeiffer has become involved in many multicenter collaborations within the VA system, and he was the Principal Investigator of a CDC-funded project entitled, "Preventing Spread of Carbapenem-Resistant Enterobacteriaciae (CRE) among Veterans through an Automated Tracking System". This project culminated in the development and implementation of a novel electronic system now called VA Bug Alert (VABA) which alerts local infection prevention teams when patients with a history of MDROs such as CRE & C. auris are admitted to any VA facility. 

Dr. Pfeiffer enjoys spending time outdoors with his family walking, hiking, biking, playing tennis when he's not injured, and gardening (a.k.a. cleaning the yard).