Outside of politics, Yen works as an anesthesiologist. He witnessed Oklahoma's October 28, 2021 execution of John Grant with a three-drug lethal injection protocol and testified as an expert for the state Attorney General's office, at a rate of $250 per hour, that the prisoner was fully unconscious despite some witnesses claiming they observed him struggling to breathe, convulsing, and vomiting on the execution gurney.[3][4]
Oklahoma Senate
Previously registered Democrat, Yen changed his party affiliation to Republican in 2009.[5] He ran for the District 40 state senate seat against Brian Winslow, Joe Howell, Steve Kern, David B. Hooten, and Michael Taylor in a Republican primary in 2014. He defeated pastor Steve Kern in a runoff.[6] He defeated Democrat John Handy Edwards in the general election. Yen is the first physician in the Oklahoma Senate in 40 years. He is also the first Asian American in the legislature in Oklahoma history.[7]
Yen supports only medical exemptions to school vaccinations and introduced bills to that effect in the 2016 and 2017 legislative sessions.[8]
Yen was instrumental in passing a bill outlawing texting while driving and authored a bill which became law that kept children from using commercial tanning beds.
Yen lost his 2018 primary election to veterinarian Joe Howell, whose campaign was largely financed by the Oklahomans for Vaccine and Health Choice, an anti-vaccination group.[9][10]
In February 2019, Yen received the American Medical Association's Dr. Nathan Davis Award for Outstanding Government Service as a State Legislator.[11]
