Rear Adm. Brian S. Pecha received his bachelor’s degree in 1983 from the University of San Francisco and a medical degree from Stanford University School of Medicine in 1988. He completed residency training in internal medicine at Naval Hospital San Diego, where he served as chief of residents. In 1991 he was assigned to Naval Hospital, Naples, Italy, as a staff internist and department head, and for the final year of his tour was director of Medical Services. He graduated in 2004 "with distinction" from the distance education program at the Naval War College. In 2010, he completed Phase II of Joint Professional Military Education at the Joint Forces Staff College in Norfolk.
Pecha entered civilian practice in 1994 and re-affiliated with the Navy Reserve the following year. Since then his reserve assignments have included Naval Reserve Hospital Oakland, Fleet Hospital 9, Naval Reserve Hospital Bremerton, Operational Health Support Unit Camp Pendleton, 1st Battalion 14th Marines, 4th Marine Division, Headquarters Marine Forces Reserve, and Headquarters Bureau of Medicine and Surgery. During these reserve roles he has served as a training officer, administrative officer, assistant officer-in-charge, officer-in-charge, Battalion Surgeon, Division surgeon, force surgeon, and chief of the Navy Reserve Medical Corps. From January 2011 to December 2012 he commanded 4th Medical Battalion, 4th Marine Logistics Group, in San Diego.
In 2002 he was recalled to active duty and assigned as senior medical officer for the Branch Medical Clinic at Marine Corps Air Station Yuma. In 2006, he was recalled with 1st Battalion 14th Marines, deploying to Anbar Province in Iraq as the surgeon for Task Force Military Police, a major subordinate command of the 1st Marine Expeditionary Force. In March 2013, he was brought to active duty as the force surgeon for Marine Forces Reserve in New Orleans, and upon promotion in October 2013 was recalled again for a year as the medical officer of the Marine Corps. From Feb 2016 to Feb 2018 he was recalled to serve as command surgeon for U.S. Pacific Command in Honolulu.
He earned the Fleet Marine Force Officer Warfare Qualification in 2006. His personal decorations include the Defense Superior Service Medal, Meritorious Service Medal (two awards), Navy and Marine Corps Commendation Medal (three awards), Navy and Marine Corps Achievement Medal (two awards), Navy Unit Commendation Medal, Meritorious Unit Citation and various campaign and service medals.
In civilian practice, Pecha is the medical director at Sonoma Developmental Center for persons with intellectual disabilities. He has been certified and recertified by the American Board of Internal Medicine since 1991, and was elected to fellowship in the American College of Physicians in 1998.