The Athletics signed Leiter to a one-year, $3 million contract Thursday, Jesse Rogers of ESPN.com reports.
Leiter was non-tendered by the Yankees last month after posting a 4.84 ERA and 1.53 WHIP over 48.1 regular-season innings in 2025, but a 3.55 FIP and 54:17 were encouraging. He's collected a 28.3 percent strikeout rate over the past four regular seasons and could be in the mix for saves as part of an unsettled Athletics bullpen.