“David M. Walker, the U.S. comptroller general and head of the Government Accountability Office, announced Friday that he will resign in March to lead a new foundation focused on long-term public policy challenges.

GAO serves as Congress’ chief investigative and audit arm, probing waste and fraud in government programs and detailing the long-term budget problems facing the government. Walker has headed the agency, which has more than 3,100 employees and a budget of nearly $500 million, since November 1998. His 15 year-term was not set to end until 2013.

Walker, 56, has repeatedly warned that the government faces a long-term fiscal crisis as the baby-boom generation retires, driving up spending on Medicare, Medicaid and Social Security.

He will continue to raise the alarm as president and chief executive of the newly established Peter G. Peterson Foundation, set up by the co-founder and senior chairman of The Blackstone Group, who served as Commerce secretary in the Nixon administration. Peterson has pledged to contribute at least $1 billion to the foundation.

“I have been around a very long time, and I have never seen so many simultaneous challenges that I would describe as undeniable, unsustainable and virtually untouchable politically,” Peterson, 81, said in a release announcing the foundation.”

More at Congressional Quarterly.