How I Met Your Mother Season 9 spoilers include episode titles, U.S. premiere date, and some recurring guests. Here's what IBT has gathered, so far.

There will be 24 episodes in the ninth and final season of How I Met Your Mother. Season 9 features Cristin Milioti among the regular cast as the titular mother. The premiere episode is called "The Locket," and it will run on Sept. 23 (Monday) via CBS.

RELATED | How I Met Your Mother Season 9 Spoilers: Mother Dies and Marshall Wins the Ted and Robin Bet? The Wedding Unfolds! [PHOTOS]

HIMYM fans can expect to see a lot of flashbacks and flash forwards in How I Met Your Mother Season 9. The entire farewell chapter happens during Barney's and Robin's wedding weekend, which means narrator Ted Mosby will be hopping from one time frame to another.

Several favourite guests are expected to show up in HIMYM Season 9. Barney's dad Jerome Whittaker (John Lithgow) and Robin's dad Robin Scherbatsky Sr. (Ray Wise) will be there. James Stinson (Wayne Brady) is returning, too. Robin's younger sister Katie (Lucy Hale) could also re-appear.

But one of the most anticipated HIMYM Season 9 guests is Robin's mom, the former Mrs Scherbatsky. To add some flavour of madness into the wedding, Robin's stepmom gets in the picture, too.

"We'll be exploring why Robin hasn't talked to her [mom]," Carter Bays told TV Guide. Meanwhile, Robin's stepmom wants to sing at her wedding.

How I Met Your Mother Season 9: Series Ending to Launch Spin-off Sitcom?

A TV Guide report mentioned How I Met Your Mother Season 9 may not be the end for Ted Mosby and/or his friends.

After NBC's 10-year run of "Friends," there was "Joey." Will HIMYM, the modern-day Friends-like sitcom, also launch a spin-off series featuring one or two of HIMYM characters?

William Keck of TV Guide wrote Carter Bays, co-creator of 'How I Met,' is "not ruling out the possibility of a relationship-themed spinoff."

Here are some of the possible How I Met Your Mother spin-off ideas:

1. 'How I Met Your Father' A Cristin Milioti show chronicling the mother's dating and relationships history with friends and family.

2. Barney Stinson. Just Barney Stinson post-divorce (assuming some fans are correct in forecasting a Scherbatsky-Stinson eventual divorce).

3. Marshall and Lily. A show about the Eriksen-Aldrin family. There's quite an issue, though: Alyson Hannigan might be okay, but Jason Segel might not come on board. It will be recalled that Jason was the last to sign on for How I Met Your Mother Season 9. The actor has been very busy with other showbiz endeavors.

4. Ted Mosby's Dating Rules. A show in which Future Ted is still a mere narrator in the show. Bob Saget's voice will tell the story of mundane family life or some guy(s) dating his daughter.

5. James Stinson. Wayne Brady, who plays Barney's brother, is one of the favourite recurring guests in the sitcom. How I Met Your Mother Season 9 spoilers have revealed Brady is definitely joining the gang next season. If the character gets his own show, fans can continue to imagine that anytime, Ted and the rest of the gang can drop by and chat.

More 'How I Met Your Mother,' TV Guide Features:

'How I Met Your Mother' Real Nerd Must-Share Story: How 'McKay' the Geek Got the Gorgeous Girl [PHOTOS]
Revenge Season 3 Spoilers: Must-Watch Shocking Trailer; Writers Tease Mind-Blowing Season [PHOTOS, VIDEO]
Dexter Season 8, Episode 8 Recap, Shocking Spoilers: 'Are We There Yet' is Best 'Brain Surgeon' Episode! [PHOTOS]