Dr. Bennett is an Associate Professor at the University of Washington School of Medicine in the Department of Pediatrics, Division of Genetic Medicine. He is also a Principal Investigator in the Center for Developmental Biology and Regenerative Medicine (CDBRM) at the Seattle Children’s Research Institute.

His research is focused on somatic mutations that arise after the single cell zygote stage and are not present in every cell in the body. These mutations are difficult to detect, require access to tissues and sensitive sequencing approaches. A central hypothesis of the lab is that "hidden" genetic variation contributes more to pediatric developmental diseases than is currently appreciated. His lab has contributed to the characterization of genetic causes of isolated vascular malformations, most of which are due somatic mutations in the PI3K-AKT or RAS-MAPK pathways. He is an investigator within the SMaHT consortium which aims to develop a catalogue of somatic mutations across numerous tissues in a cohort of 150 individuals.

In addition to research, Dr. Bennett also sees patients in pediatric genetics clinic and is a co-director of the Seattle Children’s Hospital Molecular Diagnostic lab, where he oversees a clinical diagnostic assay for detecting mutations in vascular anomalies, known as "VANSeq."