he ninth and final season of How I Met Your Mother, an American sitcom created by Carter Bays and Craig Thomas, premiered on CBS on September 23, 2013, with two episodes, and concluded on March 31, 2014. The show was renewed for the final season on December 21, 2012, after cast member Jason Segel changed his decision to leave the show after Season 8. Cristin Milioti, who was revealed as "The Mother" in the Season 8 finale, was promoted to a series regular, the only time How I Met Your Mother added a new regular cast member. Season 9 consists of 24 episodes, each running approximately 22 minutes in length.
Taking place immediately after where the previous season left off, Season 9 covers the events of a single weekend that lead up to Barney (Neil Patrick Harris) and Robin's (Cobie Smulders) wedding. During the course of the weekend, "The Mother" (Milioti) is separately introduced to Robin, Barney, Lily (Alyson Hannigan), and Marshall (Jason Segel), before finally meeting Ted (Josh Radnor). The season also features frequent flashbacks and flashforwards in order to fully integrate The Mother's character with the rest of the cast. Thomas said in an interview that Season 9 is like "the Wild West – anything can happen".Overview from themoviedb.org