Ducky has not left the series yet, despite taking a much small role following season 16. He retired from his position as NCIS's Chief Medical Examiner with his former assistant, Dr Jimmy Palmer (Brian Dietzen) taking over from his position.

What happen to Ducky on NCIS?

While McCallum is still considered part of the cast, he did reduce his role on NCIS back in 2019. After years as the Chief Medical Examiner, Ducky hung up his lab coat and turned over his role to his assistant, Jimmy Palmer. RELATED: 'NCIS' Season 18: Is Leroy Gibbs' Suspension Setting the Stage For Mark Harmon's Exit?

Is Mark Harmon leaving NCIS in 2021?

'NCIS' Says Goodbye to Mark Harmon After 18 Years

The longtime lead of the CBS series had signed on for only a limited number of episodes in 2021-22.