From the U.S. Securities and Exchange Commission to the Treasury Department, the Central Intelligence Agency to the Federal Communications Commission, lawyers in top positions across the federal government have something in common—they’re from Wilmer Cutler Pickering Hale and Dorr.

More than any other law firm, Wilmer has populated the Obama administration with high-profile alums. At least 20 partners have left the firm since 2009 for senior government posts. A handful have come back, but 17 others, including U.S. Attorney for the District of Columbia Ronald Machen Jr., Deputy Treasury Secretary Neal Wolin, Internal Revenue Service chief counsel William Wilkins and SEC Division of Corporation Finance head Meredith Cross, are still on the job.