Murthy's replacement is his deputy, Sylvia Trent-Adams, who becomes one of the first nurses to serve in the position.
Admiral Trent-Adams will for now be in an acting role.
"Two years and four months ago, I was honored to be sworn in as the 19th Surgeon General of the United States", Murthy wrote.
Still, the manner in which the Trump administration sacked Murthy on Friday left little doubt about the deep partisanship that is infecting Washington DC, where even the Surgeon-General's post, a largely ceremonial bully pulpit office that counsels the nation on its health, is under the gun.
He was confirmed on December 14, 2014, and co-founded Visions, an HIV/AIDS educational program in India and the United States.
Belen Rodriguez confida: "rendo i miei ex più fighi"
Sono pochi rispetto ai "no" che ho detto (...) In realtà ho avuto solo quattro fidanzati, siamo sotto la media. Belen Rodriguez confessa di aver avuto solo 10 uomini nella sua vita .
"Dr. Murthy is another in a long list of political targets by the Trump administration".
Similarly, the New York Times - the so-called bastion of social justice activism - bleated in a snobby headline: "Nurse Replaces Surgeon General After Obama Appointee Resigns".
Murthy, an Obama administration holdover, was asked to resign by the Trump administration on Friday.
Health department spokeswoman Alleigh Marre says Murthy will remain a member of the US Public Health Service Commissioned Corps. If she was qualified to be second in line to the Surgeon General's post in 2015, why is she suddenly unqualified now? Prior to becoming surgeon general, Murthy worked as an attending physician and instructor at Brigham and Women's Hospital at Harvard Medical School. As a result of intense opposition from the National Rifle Association, the White House delayed his appointment in 2014. She served as an Army nurse officer and holds a bachelor's degree in nursing, a master's degree in nursing and health policy, and a doctorate in philosophy.
Murthy, 37, was born in England to parents from India and grew up in Miami, Florida.