Halter entered the public sector, serving as an economist to the U.S. Congress Joint Economic Committee and as chief economist for the U.S. Senate Committee on Finance. Following the election of fellow Arkansan Bill Clinton as President of the United States, Halter joined the new administration as a senior adviser in the Office of Management and Budget (OMB) in 1993. He advised on a range of policy issues, reviewed and evaluated budgets and management practices of Federal cabinet departments, presented budget options to the President, and formulated Administration positions on domestic and international policy issues. He also coordinated the work of the President's Management Council, a group consisting of the Chief Operating Officers of the Federal Cabinet departments.