Threshold Editions tells The Associated Press on Wednesday that "When the Center Held" is scheduled for publication in May.
Rumsfeld was chief of staff and then defense secretary under Ford, who became president in 1974 after the Watergate scandal led to Richard Nixon's resignation. Rumsfeld says in a statement that he'll offer Ford as proof that leaders can "rise to the challenge" when needed most.
Previous books by Rumsfeld include the best-selling "Known and Unknown: A Memoir," which includes some reflections on the Ford years.
Financial terms for the new book were not disclosed.
Rumsfeld is represented by the Washington-based Javelin agency, whose other clients include former FBI head James Comey.
Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.