Dr. Hyun Don Yun is a triple board-certified physician in internal medicine, hematology, and medical oncology, with extensive clinical, academic, and research experience.

He currently serves as an Assistant Clinical Professor in the Division of Hematology and Oncology at the University of California, Irvine, a role he has held since April 2023. He also holds a position with VA Long Beach Healthcare System. Dr. Yun has advised that he plans to open his own private practice in Irvine and resign from his positions with VA Long Beach and UCI in late August.

Prior to his current academic and clinical roles, Dr. Yun practiced at Compassionate Cancer Care Medical Group in Riverside, California from 2021 to 2022, and served as an Assistant Professor in the Division of Hematology, Oncology, and Stem Cell Transplantation at Rush University Medical Center in Chicago, Illinois from 2019 to 2021.

Dr. Yun completed his hematology-oncology fellowship at the University of Minnesota from 2015 to 2018 and his internal medicine residency at Harbor Hospital Center in Maryland from 2009 to 2012. He earned his medical degree from Pusan National University in South Korea, where he also completed his premedical training.

In addition to his clinical and academic work, Dr. Yun is committed to global health and has participated in numerous short-term medical missions in Mexico, Thailand, and Costa Rica between 2022 and 2025, providing treatment, education, and public health outreach in underserved regions.

He has been recognized with several awards, including the Young Investigator Award from the American Initiative in Mast Cell Disease in 2019, as well as research honors from the Minnesota Society of Clinical Oncology and the AMA Resident and Fellow Section.

Dr. Yun’s expertise spans internal medicine, hematology, medical oncology, translational research, and global medical service. He brings a strong commitment to advancing patient care through compassionate clinical practice, academic leadership, and scientific innovation.