Kate Walsh is set to recur in the upcoming 19th season of “Grey’s Anatomy,” returning as Dr. Addison Montgomery, the character she’s played since the Season 1 finale of the medical drama in 2005. Walsh’s Addison was also the central character on “Private Practice” — the first “Grey’s” spinoff — which ran for six seasons on ABC, from 2007 to 2013.

Walsh appeared on “Grey’s” last season in a multi-episode arc, in which Addison returned to Grey Sloan Memorial in order to perform a uterine transplant on a patient, who later miscarried. During her Season 18 appearances, Addison grieved the death of her ex-husband Derek (Patrick Dempsey) with his sister Amelia (Caterina Scorsone) and his widow Meredith (Ellen Pompeo).

In an interview last year, Walsh was enthusiastic about returning to “Grey’s” to play Addison for the first time since “Private Practice” had ended, saying “I was very satisfied and delighted by it.” She also left the door open for more. “Nobody knows what the future holds,” Walsh said at the time. “But for now, this is what we’ve got planned: just to have Addison pop in and we’ll see what happens, what transpires.”

Addison will indeed be popping back in: Her first appearance will be in the third episode of the new season.

Season 19 of “Grey’s Anatomy” premieres on ABC on Oct. 6, and Pompeo — around whom the show has revolved since its 2005 premiere — will for the first time have a reduced role as Meredith. As was announced in August, though Meredith’s narration will continue to begin and end every episode, Pompeo (also an executive producer) will appear in only eight episodes this season. Under her Calamity Jane production company, she is producing and starring in an upcoming untitled limited series for Hulu.

Pompeo is irreplacable, of course, but a slew of cast members have been added to “Grey’s” to play the new surgical interns at the hospital, including Harry Shum Jr., Adelaide Kane, Alexis Floyd, Niko Terho and Midori Francis.

“Grey’s” — created by Shonda Rhimes, and run by executive producer Krista Vernoff — continues to be ABC’s No. 1 scripted series.