Keith Fontenot, one of President Obama’s top budget experts who had a hand in shaping Obamacare, is leaving the White House for the Brookings Institution.

Fontenot joined the Office of Management and Budget with President Obama’s first budget director, Peter Orszag, and was a major part of writing the president’s signature health care law, the Hill reports. Fontenot also helped push the administration’s health care priorities in the 2009 stimulus bill.

“Keith Fontenot has played an integral role in moving this Administration’s health agenda forward — from historic changes bringing affordable health care to millions, to thoughtful reforms in health programs that are bringing down costs and improving value for all Americans,” acting OMB Director Jeff Zients said, according to the Hill.

Fontenot’s public career included OMB, the Centers for Medicare and Medicaid Services, the Congressional Budget Office and the Social Security Administration, the Hill reports.