Per The Hollywood Reporter 'NCIS' Renewed for Two Seasons at CBS: At "it's inception" this was the regular cast: At the end of Season 15, Pauley Perrette still won't be old enough to receive that membership invitation letter from AARP as she'll only be 49. But Harmon will be on Medicare. And Sasha Alexander will be retired from "Rizzoli & Isles" at age 44. Oddly when Emily Wickersham joined the cast as a regular I thought she was kind of young. It turns out she was about the same age as Alexander was when the show started. I'll keep watching because somehow they keep coming up with decent episode story arcs. But the show is getting a little long-in-the-tooth.