Kathleen Sebelius was the only nominee still awaiting confirmation
President Barack Obama has sworn in the new health secretary, the former Kansas governor, Kathleen Sebelius, after her appointment was backed by the Senate.
Senators approved her appointment by 65 votes to 31.
Republicans had delayed the confirmation over Kathleen Sebelius' support for abortion.
But Democrats said the post needed to be filled quickly as the government reacts to an outbreak of swine flu that has infected 64 people in the US.
After the Senate vote, Ms Sebelius flew to Washington and took the oath of office.
"We wanted to swear her in right away because we've got a significant public health challenge that requires her immediate attention," said President Barack Obama.
"We need all hands on deck," he said.
During confirmation hearings, Ms Sebelius had came under fire after acknowledging that she had found what she called "unintentional errors" in her tax returns.
Mr Obama's appointment of a health secretary had already been delayed when his first choice, Tom Daschle, stepped down over questions about his taxes.
The health position was the last remaining seat to be filled in Mr Obama's cabinet.
The US president has made an overhaul of the healthcare system one of his domestic priorities.
Ms Sebelius has been replaced as governor of Kansas by the state's Lieutenant Governor Mark Parkinson.