Jackie Norris will become a senior adviser to the Corporation for National and Community Service.
Replacing Norris as chief of staff will be Mrs. Obama's longtime friend Susan Sher. Sher joined the administration as an associate counsel to the president. Sher and Mrs. Obama worked together at the University of Chicago Medical Center.
Norris worked on the president's campaign in Iowa.
Norris will continue to work with the first lady's office and the administration as it implements a new law to expand national community service programs.