The Obamacare critic Azar, 50, had until last January served as president of Lilly USA, the American arm of drug giant Eli Lilly and Company.
The Yale Law graduate Azar also had served as general counsel and then as deputy secretary of HHS in the administration of President George W. Bush.
If his nomination is approved, Azar would replace Trump's first HHS chief, Dr. Tom Price, who resigned
Azar's prospective department has the biggest budget of any single agency in the federal government — more than $1 trillion.
HHS oversees the sprawling Medicare and Medicaid programs, which together proved health insurance coverage to almost 130 million Americans.
HHS is also resonsible for overseeing the Affordable Care Act, popularly known as Obamacare.
Government-run ACA exchanges sell private health insurance plans to more than 10 million people, and the law also expanded Medicaid coverage to more than 10 million other people.
Azar in February, during an interview on CNBC in February, said "The remarkable thing here is Obamacare is failing completely on its own terms."
Speaking about what was then a prospective Republican Obamacare repeal-and-replacement bill, Azar said there was a consensus among Republicans and Democrats that the government should play a role in expanding insurance coverage and subsidizing its purchase by individuals. But he suggested that the way to do that was one other than Obamacare's system.