Worth’s last day is today and he will join the think-tank on 11 June.
He will report to Policy Exchange director Neil O'Brien and head up a six-month project on public services reform. The project aims to use innovations to improve the quality of public services at a time where budgets are being cut.
Worth spent the past two years in Downing Street working on a number of areas of public services reform.
He had recently been seconded to the Department of Health in what was seen by the media as Downing Street parachuting in media help. While there, Worth helped Health Secretary Andrew Lansley with his NHS reforms.
Before joining Downing Street he was head of the Conservative Party's policy unit, where he worked on proposals to improve public services that helped form current coalition policies.
Worth’s appointment follows that of James O'Shaughnessy, the former head of policy at Downing Street, who works for the think-tank part-time due to his commitments at Portland.