[9] On August 1, 2022, the Yankees traded Medina, JP Sears, Ken Waldichuk, and Cooper Bowman to the Oakland Athletics in exchange for Frankie Montas and Lou Trivino.

In three starts, he registered a 3.86 ERA with 11 strikeouts in 9+1⁄3 innings of work before the Athletics promoted Medina to the major leagues on April 25.

[12] He made 23 appearances (17 starts) for Oakland in his rookie campaign, logging a 3–10 record and 5.42 ERA with 106 strikeouts across 109+2⁄3 innings pitched.

Medina began the 2024 season on the injured list after suffering a Grade 2 medial collateral ligament sprain in spring training.

On July 25, it was announced that Medina would require Tommy John surgery to repair ligament damage in his elbow, ending his season.