WASHINGTON (AP) — Social Security Commissioner Michael J. Astrue says he will step down in February after completing his six-year term. Astrue's departure gives President Barack Obama the opportunity to name a new head to the federal government's largest program.

Astrue's term was marked by increasingly dire warnings about the long-term financial health of the massive retirement and disability program. Astrue worked to reduce backlogs of people applying for disability claims, despite a big surge in applications since the recession.

The trustees who oversee Social Security project that the program's trust funds will run dry in 2033. At that point, Social Security will collect only enough in taxes to pay 75 percent of benefits. As commissioner, Astrue is also a trustee.

Astrue has urged Congress to shore up the program's finances but has not publicly endorsed any solutions.

Astrue, 56, said he plans to return to his home state of Massachusetts. He did not elaborate on future plans.

"I consider it a great privilege to have led this remarkable agency for six years," Astrue said in a statement.

Social Security commissioners serve six-year terms. Astrue was nominated in 2007 by former President George W. Bush. The term of Obama's nominee would last beyond his presidency, if the person serves a full term. There was no word Monday on Obama's choice.

Astrue has a long history of public service. He previously worked as counselor to the Social Security commissioner and general counsel for the agency. He was also an acting deputy assistant secretary for the Department of Health and Human Services.