FACTBOX: Douglas Elmendorf, U.S. Congress' budget watchdog

(Reuters) - Congressional Budget Office director Douglas Elmendorf is expected to reiterate on Tuesday that the U.S. government faces huge deficits for years to come, news that could hinder President Barack Obama's policy plans.

Following are some facts about the head of the nonpartisan analysis service of Congress:

* Appointed by Democratic leaders in January, Elmendorf heads an agency of 235 people that helps Congress set economic policy by analyzing the impact of legislation on the federal budget.

* Elmendorf has played a prominent role in the healthcare reform debate, delivering sometimes unwelcome news on cost projections to Democrats trying to pass Obama's top domestic policy priority.

* In June, he told the Senate that one of its proposals to expand healthcare coverage would increase the deficit by about $1 trillion over 10 years and still leave millions of Americans without insurance.

* In July, he told Congress the healthcare bills being drafted by Democrats would not rein in long-term costs and that government expenses will rise if healthcare is expanded.

* It is not the first time Elmendorf has weighed in on healthcare reform. As a CBO analyst in 1994, he was on a team that concluded President Bill Clinton's effort would cost more than previously thought and greatly expand the government's role. The effort died shortly thereafter.

* Elmendorf, a native of Poughkeepsie, New York, graduated from Princeton University in 1983 and received a PhD in economics from Harvard University in 1989. His advisers at Harvard included Larry Summers, now Obama's top economic adviser, and Martin Feldstein and Gregory Mankiw, who have advised Republican presidents.

* After his first stint at CBO, Elmendorf worked under Clinton on the Council of Economic Advisers and in the Treasury Department. He has held several positions at the Federal Reserve and most recently worked at the Brookings Institution, a liberal-leaning think tank.

(Reporting by Andy Sullivan in Washington; Editing by John O'Callaghan)