Chandra Wilson has also been there since the very beginning, and she also directed the milestone episode.
"I think we saw the number a while ago, we knew how many we would have to do to get there, but actually being here is a whole other thing. It's really exciting," she told us. "It's kind of unheard of a little bit. We're in our own little club. It's very cool."
"It feels amazing," Justin Chambers says when Camilla Luddington asks what it's like to have been in every single episode. "I mean it's the majority of my adult life. It's been amazing."
Chambers says that he was always telling himself "two more years," which obviously hasn't yet been accurate.
"The Justin who showed up for the pilot, for many years, kept saying, 'two more years, right guys, two more years' on set in between takes. And naysayers would be like, eh, we got maybe two, maybe we got three. Well cut to season 15...So Justin, 14 more years, just shut up."
"We're here 'cause of the fans because they tune in every week, and we know how lucky we are to even get to season 15," Luddington says.
The next big record is longest running TV drama, which is currently held by Gunsmoke at 635 episodes.
"Ha! I'd have to start over again to get to Gunsmoke," Wilson said when we asked if they could make it. "From like a historical standpoint, I would love to be able to stay I was a starter and a finisher. Actors don't get the opportunity to do that, especially not on something that runs this long. So I would love to be able to have that personal star that I could put on my wall and stay that I started and finished a thing...so you know, until the wheels fall off, I guess."
James Pickens Jr. was also a starter, and he also hopes to be a finisher.
"I've had such a great time doing it, obviously, and to be at this point in my career and still have a job, a steady gig, it's hard to say hey maybe it's time to hang up," he says. "But when it is that time, for it to finally say goodbye, I want to come in and turn off that OR light for the last time and have the show end right there."
For more from the entire cast, watch the videos above.
Grey's Anatomy airs Thursdays at 8 p.m. on ABC.