President-elect Donald Trump on Tuesday tapped Dr. Mehmet Oz, a former television talk show host and heart surgeon, to head the agency that oversees health insurance programs for millions of older, poor and disabled Americans and selected Wall Street executive Howard Lutnick to lead the Commerce Department.

“Dr. Oz will be a leader in incentivizing Disease Prevention, so we get the best results in the World for every dollar we spend on Healthcare in our Great Country,” Trump said in a statement. “He will also cut waste and fraud within our Country’s most expensive Government Agency, which is a third of our Nation’s Healthcare spend, and a quarter of our entire National Budget.”

Oz, who ran a failed 2022 bid to represent Pennsylvania in the U.S. Senate, has been an outspoken support of Trump and in recent days expressed support for Robert F. Kennedy Jr.’s nomination for the nation’s top health agency, the Department of Health and Human Services.

As the administrator for the Centers for Medicare and Medicaid Services, Oz would report to Kennedy. If confirmed by the Senate, Oz would be responsible for the programs — Medicaid, Medicare and the Affordable Care Act — that more than half the country relies on for health insurance. Medicaid provides nearly-free health care coverage to millions of the poorest children and adults in the U.S. while Medicare gives older Americans and the disabled access to health insurance. The Affordable Care Act is the Obama-era program that offers health insurance plans to millions of Americans who do not qualify for government-assisted health insurance, but do not get insurance through their employer.

“Americans need better research on healthy lifestyle choices from unbiased scientists, and @robertfkennedyjr can help as HHS secretary,” Oz shared in a post on Instagram last week, along with a photo of him and Kennedy together.

Oz has been accused of hawking dubious medical treatments and products on his defunct TV show. And during the height of the COVID-19 pandemic, he pressured government officials to make hydroxychloroquine widely available, despite unresolved questions about its safety and effectiveness.

Lutnick, meanwhile, will have a key role carrying out Trump’s plan to raise and enforce tariffs as commerce secretary, Trump said on Tuesday. Lutnick is a cryptocurrency enthusiast and head of brokerage and investment bank Cantor Fitzgerald.

Trump made the announcement Tuesday on his social media platform, Truth Social. In the post, Trump said Lutnick “will lead our Tariff and Trade agenda, with additional direct responsibility for the Office of the United States Trade Representative.”

Lutnick is a co-chair of Trump’s transition team, along with Linda McMahon, the former wrestling executive who previously led Trump’s Small Business Administration. Both are tasked with putting forward candidates for key roles in the next administration.

The nomination would put Lutnick in charge of a sprawling Cabinet agency that is involved in funding new computer chip factories, imposing trade restrictions, releasing economic data and monitoring the weather. It is also a position in which connections to CEOs and the wider business community are crucial.

An advocate for imposing wide-ranging tariffs, Lutnick told CNBC in September that “tariffs are an amazing tool for the president to use — we need to protect the American worker.” Trump on the campaign trail proposed a 60% tariff on goods from China — and a tariff of up to 20% on everything else the United States imports.

Mainstream economists are generally skeptical of tariffs, considering them a mostly inefficient way for governments to raise money and promote prosperity.

Lutnick had been considered for treasury secretary, a role that has been at the center of high-profile jockeying within the Trump world. At the same time, the treasury position is closely watched in financial circles, where a disruptive nominee could have immediate negative consequences on the stock market, which Trump watches closely.

The news also comes after billionaire Elon Musk and others in Trump’s orbit called on Trump to dump previous front-runner for treasury secretary, Scott Bessent, in favor of Lutnick. Musk said in his post that “Bessent is a business-as-usual choice, whereas @howardlutnick will actually enact change.”

Lutnick joined Cantor Fitzgerald in 1983 and rose through the ranks to be appointed president and CEO in 1991.

Lutnick also chairs financial technology company BGC Group, Inc. and the commercial real estate services firm Newmark Group, Inc.

Lutnick has donated to both Democrats and Republicans in the past, and once appeared on Trump’s NBC reality show, “The Apprentice.” He has become a part of the president-elect’s inner circle, and has shared the stage with Trump at events in the closing days of his campaign, including a rally at Madison Square Garden.

He came under criticism in the campaign’s final days for an interview with CNN in which he repeated Robert F. Kennedy Jr.’s debunked criticisms of vaccines.