The Trump administration has relieved Dr. Vivek Murthy of his duties as U.S. Surgeon General.
A spokeswoman for the Department of Health and Human Services says Murthy was asked to resign after "assisting in a smooth transition" under President Donald Trump.
Murthy was a holdover from the Obama administration.
Murthy's deputy, Rear Admiral Sylvia Trent-Adams, is serving as acting surgeon general and leader the U.S. Public Health Service Commissioned Corps until the Senate confirms a replacement. Her previous positions include being a nurse officer in the U.S. Army.
Health department spokeswoman Alleigh Marre says Murthy will remain a member of the U.S. Public Health Service Commissioned Corps.
Murthy says on Facebook that he was humbled and honored to serve. He says serving was the "privilege of a lifetime."