President-elect Donald Trump has picked Dr. Mehmet Oz to serve as the administrator for the Centers for Medicare and Medicaid Services.

“I have known Dr. Oz for many years, and I am confident he will fight to ensure everyone in America receives the best possible Healthcare, so our Country can be Great and Healthy Again!” Trump said in a statement on Tuesday.

Oz, a cardiothoracic surgeon and television personality, ran unsuccessfully for Senate in 2022 in Pennsylvania with Trump’s backing. He lost to Democratic now-Sen. John Fetterman.

In 2018, Trump appointed Oz to the Presidential Council on Sports, Fitness and Nutrition, reappointing him to the position in 2020.

Oz rose to fame as a frequent guest of Oprah Winfrey, eventually launching his own syndicated daytime TV talk show in 2009. Through “The Dr. Oz Show,” which won several daytime Emmy awards and reached millions of viewers, Oz became one of the most well-known doctors in the country.

His views on Covid-19, however, sparked controversy. Early on in the pandemic, for instance, Oz talked up the antimalarial drug hydroxychloroquine as a way to treat the coronavirus — despite the lack of firm scientific evidence that it was an effective treatment.

While many of those perspectives were praised by Republicans at the time, Oz before running for Senate regularly supported health insurance mandates and promoted Obamacare, CNN’s KFile reported — taking unusual positions for a GOP candidate.

As a physician, for example, Oz advocated that everyone in America have insurance and said the government should provide health care coverage to Americans who cannot afford it. “It should be mandatory that everybody in America have healthcare coverage. If you can’t afford it, we have to give it to you,” Oz told The Seattle Times in 2009.

Oz, who is an advocate of alternative medicines and treatments, has been skewered by the medical community for years. In 2015, a group of physicians wrote Columbia University, saying they were “dismayed” Oz was a member of the school’s faculty. And in 2014, Oz was scolded by senators during a congressional hearing over his promotion of weight-loss products on his television show.

Oliver Darcy contributed to this report.

This story has been updated with additional information.