Kayce Dutton’s world is expanding to the badge: CBS has rounded out the ensemble for Y: Marshals, adding Yellowstone veterans Gil Birmingham, Mo Brings Plenty, and Brecken Merrill as series regulars alongside Luke Grimes, with Arielle Kebbel, Ash Santos, and Tatanka Means also joining the cast. The series follows Kayce’s move into an elite U.S. Marshals unit in Montana, blending his cowboy background and Navy SEAL training while weighing the toll on family and duty; Logan Marshall-Green co-stars as Pete Calvin, a friend from Kayce’s military past.
Positioned as a procedural anchored in Sheridan’s frontier ethos, the show carries the working title Y: Marshals and is slated to launch midseason in the 2025–26 broadcast cycle, airing Sundays at 9 p.m. ET on CBS in a 13-episode run. Scheduling materials also emphasize that the title remains provisional.
Behind the camera, SEAL Team alum Spencer Hudnut serves as showrunner and executive producer, with the opening episode written by Hudnut and directed by Greg Yaitanes, a pairing that signals a muscular, case-driven format with character-centric stakes. The official series logline frames Kayce and his teammates as the region’s “last line of defense” amid rising violence, underscoring a balance between action and the psychological costs borne by law enforcement families.
The return of Birmingham’s Chief Thomas Rainwater, Brings Plenty’s trusted aide Mo, and Merrill’s Tate Dutton ties the new show to the political and personal currents that powered Yellowstone, hinting that Kayce’s federal cases will intersect with tribal sovereignty and long-simmering land disputes as much as with fugitive hunts. While the full roster of returning characters remains unannounced, recent network guidance notes the working-title status and midseason berth, leaving room for additional casting reveals as production progresses.
In announcing the latest round of casting, The Wrap also named Brett Cullen in a recurring role as the U.S. Marshal in charge in Montana, a detail that, paired with the series’ procedural frame, suggests cases-of-the-week threaded through Kayce’s evolving home life.
