The Athletics and general manager David Forst have mutually agreed to part ways, the team announced Friday.
Assistant GM Dan Feinstein has been named interim GM for the remainder of the 2026 season.
"David has been an integral part of the A's and our success for nearly three decades," owner John Fisher said. "His leadership, dedication, and commitment to this team have helped shape our baseball operations department and position us for the future. We are grateful for everything David has done for our organization."
Forst took over as the Athletics' GM after Billy Beane was promoted to executive vice president of baseball operations following the 2015 season. The Athletics first hired Forst in 2000 as a scout.
"It was truly an honor to spend the last 27 years with the A's, especially the last 11 as the GM," Forst said. "This organization is full of incredibly talented, devoted, and good people, and I am lucky to have worked alongside them for so long."
The Athletics enter Friday with a 45-70 record and sit 13.5 games behind the Houston Astros for the top spot in the AL West.
Temporarily playing their games at a Triple-A park in West Sacramento, California, the A's are scheduled to move to Las Vegas to begin the 2028 campaign.
