By Megan Riedlinger
6:00am PDT, May 29, 2023
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It's hard to believe "NCIS" is wrap[ing up its 20th season on May 22, 2023! Join us as we take a look back at the major players from the hit CBS drama series — which debuted back on Sept. 23, 2003, and was originally called "Navy NCIS: Naval Criminal Investigative Service" before abbreviating its name to the iconic acronym we know today — to see just how much they've changed over the last two decades!
Keep reading to see how Special Agents Leroy Gibbs, Forensics Speciality Abby Sciuto and more of the gang have changed…
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Does it look like 20 years have passed between these pictures? Mark Harmon seemingly discovered the fountain of youth, as he looked nearly the same on his final episodes in season 19 as he did when the CBS series began. Though it seemed like the actor hung up his hat, he hasn't ruled out an eventual return! While speaking to "Today" in 2022, Mark shared, "I'm not retired. The character is living in Alaska as far as I know."
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Pauley Perrette's character, Abby Sciuto, worked alongside Mark Harmon's Leroy Jethro Gibbs for more than a decade, serving as the show's resident forensic scientist with a penchant for gothic vibes. Her character was also featured on spinoffs "NCIS: Los Angeles" and "NCIS: New Orleans." The actress left the original show during season 15 in 2018.
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Pauley Perrette struck out on her own after leaving "NCIS" in 2018, starring on another CBS series, "Broke," which only lasted for one season in 2020.
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Brian Dietzen — who played Dr. Jimmy Palmer, an assistant medical examiner — started out as a recurring character during season 1 of "NCIS" then moved on to a starring role in season 6 and got bumped up to main-character status in season 10.
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Since becoming a main character during season 10, Brian Dietzen's Dr. Jimmy Palmer has become a focal point of the show with dramatic storylines that include losing his wife to COVID-19 in season 18. In season 16, he also got a major promotion — moving from assistant medical examiner to acting chief medical examiner.
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Sasha Alexander starred on the first three seasons of "NCIS" as Special Agent Caitlin Todd. She's continued to appear via flashbacks and CGI footage throughout the show's 20 seasons.
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After leaving "NCIS" in 2005, Sasha Alexander continued to be a fixture on the small screen. The actress starred on "Rizzoli and Isles" as Maura Isles from 2010 to 2016 then appeared on "Shameless" from 2015 to 2016. More recently, she popped up on an episode of "Law & Order" in 2023.
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David McCallum has played lovable and odd Dr. Donald "Ducky" Mallard since the show's start. He was the chief medical examiner until 2019, when he took on another job…
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He's barely aged a day! David McCallum continues to play Dr. Donald "Ducky" Mallard, though he moved from chief medical examiner to NCIS historian in season 16.
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We've seen Sean Murray as Special Agent Timothy McGee (right) on "NCIS" since season 1. (He's seen here with Special Agent Anthony Dinozzo, who was played by Michael Weatherly — we'll get to him later!) Aside from his day job, Timothy writes mystery crime novels under a pseudonym.
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Sean Murray continues to star as Timothy McGee, though he got a big promotion. He currently works as a senior field agent on the show.
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From seasons 1 to 13, Michael Weatherly brought Special Agent Anthony Dinozzo to life on "NCIS." The senior field special agent and former homicide detective is a bit of a lady's man who struck up a romance with co-worker Ziva David before departing the show in season 13 following her death.
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Michael Weatherly continues to be a TV fixture. The same year he left "NCIS," he landed a starring role on CBS's "Bull," which ran from 2016 until 2022.
