What began as a spinoff of JAG has grown into one of television’s most enduring franchises – and now NCIS is closing in on an incredible milestone: its 500th episode.

With Season 23 currently airing, longtime fans know there’s no one better to reflect on that achievement than Sean Murray, who has played Special Agent Timothy McGee for nearly the entire run of the series.

Speaking with CinemaBlend, Murray shared why he believes NCIS continues to thrive more than two decades in.

“It’s great – especially because we’re always trying to push forward,” Murray explained. “Even at 500 episodes, we’re not resting on our laurels. We’re still trying new things and telling different kinds of stories.”

Since debuting in Season 1 and eventually taking top billing following Mark Harmon’s exit, McGee has evolved alongside the show. Murray credits NCIS’ longevity to its willingness to change instead of sticking to a rigid formula.

And fans should brace themselves – because Murray teased that Season 23 has some major surprises ahead.

“There are things coming this year that will have jaws on the floor,” he said. “Not fake-outs – real, shocking developments involving multiple characters.”

So far, Season 23 has already delivered big moments, from spotlighting McGee’s author alter ego to revisiting long-cold cases and expanding Alden Parker’s backstory. But according to Murray, the biggest twists are still to come.

“To be doing this after 500 episodes and still feeling excited – I’ve never gotten bored for a moment,” he added. “We’re firing on all cylinders this year. I’m really proud of what we’re doing.”

While CBS hasn’t announced the exact airdate for Episode 500 yet, fans can continue watching NCIS Tuesdays at 8 p.m. ET on CBS, with episodes also streaming on Paramount+.

After all these years, NCIS isn’t slowing down – it’s still finding new ways to surprise.