US President Barack Obama has named his budget director to take over the reins of the nation's troubled health insurance reform Obamacare.
The president also defended the work of outgoing Kathleen Sebelius, who was caught in the cross hairs when the reforms were rolled out late last year.
Sebelius, 65, who came under fire for difficulties with the website where Americans were told to sign up for health care, submitted her resignation in early March, after the first period of enrolment in Obamacare had closed.
Obama named Sylvia Mathews Burwell, 48, director of the Office of Management and Budget (OMB) and a former top official at the Gates and Wal-Mart foundations, to replace Sebelius as head of the Department of Health and Human Services.
Her appointment will need endorsement from the Senate.
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Sebelius, who has served five years in the position, appeared alongside Obama in the White House Rose Garden.
She referred to the Affordable Care Act as "the most significant social change in the country" since the passage of civil rights legislation 50 years ago.
"She will go down in history for serving ... while the United States of America declared that affordable health care is not a privilege, but a right," Obama said.
Sebelius was a lightning rod for criticism in October during the first weeks of the faltering internet rollout of the president's signature public policy reform, which allowed uninsured people to buy affordable health insurance - often for the first time - from private insurers.
