Jonathan Warren, MD

Jonathan Warren, MD, is an emergency medical services (EMS) and ultrasound fellow at Harbor-UCLA Medical Center and the David Geffen School of Medicine at University of California, Los Angeles (UCLA). 

He earned his medical degree from the David Geffen School of Medicine and completed residency at Harbor-UCLA. Dr. Warren's clinical interests are prehospital ultrasound, emergency medical services, medical education, and faculty development. 

As an ultrasound fellow and health sciences clinical instructor, he teaches residents, supports faculty development in advanced ultrasound, leads quality assurance review, and develops research projects. As an EMS fellow, he teaches at the paramedic training institute, helps develop county initiatives and policies, and led the first prehospital lung ultrasound implementation and pilot study in Los Angeles County. 

His current research examines prehospital lung ultrasound for distinguishing congestive heart failure from chronic obstructive pulmonary disease, barriers to implementation, and cardiac ultrasound definitions through Delphi work. His honors include Harbor-UCLA's 2024 Academic Achievement Award and a 2025 Western Regional SAEM best EMS and prehospital care abstract award.