After retiring from the military, Mattis worked for FWA Consultants and served as a member of the General Dynamics Board of Directors.
Between 2013 and 2017, while on the board of General Dynamics, Mattis made more than $900,000 in compensation, including company stock.
In August 2013, he was appointed an Annenberg Distinguished Visiting Fellow at the Hoover Institution and in 2016 he was named the Davies Family Distinguished Visiting Fellow.

In December 2015, Mattis joined the advisory board of Spirit of America, a 501(c)(3) nonprofit organization that provides assistance to support the safety and success of American service personnel and the local people they seek to help.

He is co-editor of the book Warriors & Citizens: American Views of Our Military, published in August 2016.

From 2013 to January 2017, Mattis was a board member of Theranos, a health technology company that claimed to have devised revolutionary blood tests using very small amounts of blood.
Previously, in mid-2012, a Department of Defense official evaluating Theranos's blood-testing technology for the military initiated a formal inquiry with the Food and Drug Administration about the company's intent to distribute its tests without FDA clearance.
In August 2012 Theranos CEO Elizabeth Holmes asked Mattis, who had expressed interest in testing Theranos's technology in combat areas, to help.
Within hours, Mattis forwarded his email exchange with Holmes to military officials, asking "how do we overcome this new obstacle".
In July 2013 the Department of Defense gave Mattis permission to join Theranos's board provided he did not represent Theranos with regard to the blood-testing device and its potential acquisition by the Departments of the Navy or Defense.

In 2019, Mattis's book Call Sign Chaos: Learning to Lead was published.
It is an autobiography as well as an argument in favor of an internationalist foreign policy.
On August 7, 2019, Mattis was re-elected to the board of General Dynamics.
After retiring from the military, Mattis worked for FWA Consultants and served as a member of the General Dynamics Board of Directors. Between 2013 and 2017, while on the board of General Dynamics, Mattis made more than $900,000 in compensation, including company stock. In August 2013, he was appointed an Annenberg Distinguished Visiting Fellow at the Hoover Institution and in 2016 he was named the Davies Family Distinguished Visiting Fellow.
In December 2015, Mattis joined the advisory board of Spirit of America, a 501(c)(3) nonprofit organization that provides assistance to support the safety and success of American service personnel and the local people they seek to help.
He is co-editor of the book Warriors & Citizens: American Views of Our Military, published in August 2016.
From 2013 to January 2017, Mattis was a board member of Theranos, a health technology company that claimed to have devised revolutionary blood tests using very small amounts of blood. Previously, in mid-2012, a Department of Defense official evaluating Theranos's blood-testing technology for the military initiated a formal inquiry with the Food and Drug Administration about the company's intent to distribute its tests without FDA clearance. In August 2012 Theranos CEO Elizabeth Holmes asked Mattis, who had expressed interest in testing Theranos's technology in combat areas, to help. Within hours, Mattis forwarded his email exchange with Holmes to military officials, asking "how do we overcome this new obstacle". In July 2013 the Department of Defense gave Mattis permission to join Theranos's board provided he did not represent Theranos with regard to the blood-testing device and its potential acquisition by the Departments of the Navy or Defense.
In 2019, Mattis's book Call Sign Chaos: Learning to Lead was published. It is an autobiography as well as an argument in favor of an internationalist foreign policy. On August 7, 2019, Mattis was re-elected to the board of General Dynamics.
Jim Mattis