Senator Richard Burr, a North Carolina Republican, said he too would vote for her confirmation.

"She doesn't come with a single experience that would make a good secretary," Burr said. "She comes with a portfolio of experience. I look forward to her confirmation being quick and our ability to work together to be every bit as quick."

First Hearing

Burwell faced Congress for the first time today as the Senate Health, Education, Labor and Pensions Committee held its confirmation hearing. A hearing of the Finance Committee, which will vote on her nomination, hasn't yet been scheduled.

Today's hearing offered Republican senators a fresh, televised opportunity to level attacks on the Patient Protection and Affordable Care Act known as Obamacare, and outline possible alternatives.

In response to a question from Senator Elizabeth Warren, a Democrat from Massachusetts who said that the Congressional Budget Office projects a $500 billion decrease in Medicare spending from 2014 to 2020, Burwell said the reduction will be higher.

$900 Billion

"For the period of 2014 to 2020 health-care costs by the federal government have decreased by $900 billion over that period," Burwell said. "Hopefully those are changes that do two things: reduce costs and improve quality. The implementation already of the changes under the Affordable Care Act are reducing the deficit and providing great savings."

Burwell's position as the OMB director placed her in the center of the debate over the nation's fiscal trajectory and gave her authority over the government's regulatory apparatus. As Obama's nominee as health secretary, she argued that the Department of Health and Human Services, has made a "positive difference" in Americans' lives through its enactment of the law.

At today's hearing, Senator Lamar Alexander, a Republican from Tennessee, asked Burwell if she would let people stay on insurance plans that don't comply with Obamacare beyond 2016, when a two-year grace period allowed by the White House will expire. She didn't commit one way or the other.

"At this point I think we want to see what's happening with regard to the issues of implementation," she told Alexander.

Largest Department

Health and Human Services is the government's largest department, with a budget of about $1 trillion, including Medicare, the U.S. health plan for the elderly and disabled, and Medicaid, the program for the poor. Agencies such as the Food and Drug Administration, the National Institutes of Health and the Centers for Disease Control and Prevention also would fall under Burwell's auspices.

Alexander, the senior Republican on the health panel, outlined less comprehensive alternatives to the Affordable Care Act, including proposals to allow Americans to buy insurance sold in states other than their own and to allow small businesses to band together to purchase coverage. Republicans have long advanced such policies, which have never gained favor in Congress.

'Not Comprehensive'

"Some of our Democratic friends said: 'That's not comprehensive,'" Alexander said. "We said, 'you're right.' Washington is not wise enough to write a bill that makes so many decisions at once about 20 percent of the economy."

Republicans also pressed Burwell on the numbers of Obamacare customers who have paid their premiums, the last step to confirm enrollment. Yesterday, three major insurers including WellPoint Inc. and Aetna Inc. reported that at least 80 percent have paid their first premiums

"When will the government determine who has paid premiums and therefore is actually covered?" Senator Michael Enzi asked.

"I don't think that the insurance companies have given final numbers," Burwell responded.

She defended the administration's changes and delays to the Affordable Care Act and said the government had attempted a "common-sense implementation" of the law. Senator Pat Roberts, a Kansas Republican, said Obama unilaterally made 22 changes, including twice delaying a requirement that employers with 50 or more workers provide health insurance.

"One of the things we've tried to do is listen and hear," Burwell said, describing the delay of the so-called employer mandate as a response to concerns raised by businesses. "This is about transition to a changed system."

OMB Confirmation

The Senate voted 96-0 less than a year ago to confirm Burwell in the OMB post, and this week she met with senators to firm up support for the new position.

"We had a constructive and frank conversation that focused on the challenges of the president's signature domestic policy, Obamacare," Senator Orrin Hatch, a Utah Republican, said yesterday in a statement after his meeting with Burwell. He made clear the law, not Burwell, will be the focus of debate over her nomination.

"From skyrocketing premiums to higher taxes and fewer choices — the adverse impacts on American families, seniors and job creators continue to mount on a daily basis," he said.

Gates Connection

Burwell, 48, is a native of West Virginia and a Rhodes Scholar who served as deputy chief of staff to former President Bill Clinton. After he left office, she took a high-level job at the Bill & Melinda Gates Foundation, then was named president of the Wal-Mart Foundation in 2012. Obama nominated her to run the OMB in March 2013.

"Sylvia is a proven manager and she knows how to deliver results," Obama said at a April 11 event announcing her nomination for health secretary. "And she'll need to be a proven manager, because these are tough tasks, big challenges, you know, from covering more families with economic security that health insurance provides to ensuring the safety of our food and drug supply, to protecting the country from outbreak or bioterror attacks, to keeping America at the forefront of job- creating medical research."