While many long-running TV procedurals struggled with constant cast turnover, Blue Bloods stood out for its remarkable consistency. For all 14 seasons, Donnie Wahlberg, Bridget Moynahan, Will Estes, Len Cariou, and Tom Selleck portrayed members of the Reagan family, anchoring the CBS drama from its debut in 2010 through its finale in 2024. (Wahlberg has since moved on to film the spinoff Boston Blue, which premieres on CBS Friday, October 17, at 10/9c.)
That stability didn’t extend to everyone, however. Over the years, several of the Reagans’ colleagues and extended family members came and went. Below is a look at every series regular who exited early, along with notable recurring characters who left before the show’s final curtain call.
Flex Alexander (Detective DeMarcus King)
Flex Alexander received top billing for Blue Bloods Season 1 but appeared only in the pilot episode. He played Detective DeMarcus King, Danny Reagan’s original partner. In a 2010 interview with UrbanBridgez.com, Alexander revealed that the role was written out so Danny could be paired with a female partner instead. “It didn’t have anything to do with me or my skills,” he explained at the time.
Dylan Moore (Sydney Davenport)
Dylan Moore was also listed as a series regular during Season 1 but exited after eight episodes. She portrayed Sydney Davenport, a lawyer engaged to Jamie Reagan. The relationship ended when Sydney decided Jamie’s dangerous job placed too much strain on their future together. Unlike Alexander’s departure, the reason for Moore’s exit was never publicly disclosed.
Jennifer Esposito (Detective Jackie Curatola)
After DeMarcus King’s disappearance, Danny was partnered with Detective Jackie Curatola, played by Jennifer Esposito. Esposito left midway through Season 3, with Jackie written out on a stress-related leave of absence. At the time, CBS stated that Esposito was only available on a part-time basis, according to The Hollywood Reporter. Esposito later clarified on Twitter that her doctor had ordered a reduced workload following her celiac disease diagnosis and accused the network of placing her on unpaid leave and preventing her from taking other work. Despite the controversy, Esposito returned as a guest star during Blue Bloods’ final two seasons.
Amy Carlson (Linda Reagan)
One of the show’s most shocking exits came when Danny Reagan’s wife, Linda, was killed off-screen in a helicopter crash between Seasons 7 and 8 
later revealed to be no accident. Behind the scenes, Carlson’s seven-year contract had expired, and she chose not to renew it. “Amy decided to move on,” executive producer Kevin Wade told TV Guide Magazine after the Season 8 premiere. “I was very surprised.”
Sami Gayle (Nicky Reagan-Boyle)
Sami Gayle portrayed Erin Reagan’s daughter, Nicky Reagan-Boyle, for 10 seasons before stepping back from the series. No official explanation was given for her reduced presence, but Gayle revealed in 2023 that she had earned an MBA from the Wharton School while simultaneously starring in Bad Cinderella on Broadway. It’s likely Nicky’s on-screen move to San Francisco allowed Gayle to pursue her education and expand her career off-screen.
Despite these departures, Blue Bloods maintained a rare sense of continuity for a show that ran more than a decade. And while some characters came and went, the core Reagan family remained the steady heart of the series until the very end.