The 'Big Bang Theory' Stars Have Started Their Farewell Tour

The Big Bang Theory (CBS) TV Series Season 5 - Photofest- H 2017

The stars of CBS' The Big Bang Theory have begun their farewell tour.

On Wednesday, producers Warner Bros. Television announced that the nerdy comedy's forthcoming 12th season would be its last, with Big Bang Theory set to wrap as TV's longest-running multicamera comedy in history with 279 episodes.

While co-creator Chuck Lorre and Warners promised an "epic creative close" to the series in their statement, castmembers including Emmy winner Jim Parsons have started the process of saying goodbye to the show that made them household names (and multimillionaires).

In a lengthy Instagram post, Parsons thanked the cast, crew and fans for the opportunity to play Dr. Sheldon Cooper for 12 seasons. "I feel very fortunate that we have another 23 episodes to shoot this season because I am hopeful that with each and every one my level of really accepting this fact will sink in," the actor posted alongside an image of the cast ahead of the final season premiere taping. "I will miss all of you and all of this more than I can say and more than I can know at this time."  

Sources say the decision to end the series ultimately fell to whether Parsons wanted to return for additional episodes. Had the Emmy-winning actor desired to return another season — which CBS wanted — the entire cast would have followed suit. However, contracts for Parsons and the rest of the show's stars are up after season 12 and new mega-deals would have been needed to return for a 13th season. The cast's last deals were valued at $900,000 per episode plus points of the show's lucrative back-end as well as overall deals. (The original stars all took $100,000-per-episode pay cuts to bring Mayim Bialik and Melissa Rauch up to salary parity in a show of support that illustrates how close the cast has become over the years.)

Fellow original star Kunal Nayyar also took to social media to express his gratitude. "There are no words in any language that can describe what my heart wants to say," he wrote. "The love I feel for all of you is boundless. … Tonight I sleep with a prayer of gratitude on my lips. This isn't goodbye … yet … still 23 episodes to shoot!"

Nayyar's Raj is now the last remaining single character on the series, which has slowly and surely morphed into a family comedy. In the season 11 finale, Sheldon and Amy (Bialik) finally tied the knot in what many longtime viewers expected would be the show's endgame.

Kaley Cuoco called her Big Bang experience "a dream come true and as life-changing as it gets." She continued in an Instagram post: "No matter when it was going to end, my heart would have always been broken in two. Drowning in tears, we promise to bring you the best season yet. … We are goin out with a bang."   

Cuoco was cast after CBS rejected the original pilot for Big Bang Theory. She replaced Amanda Walsh as the character that would go on to become Penny when the show's pilot was reworked and ultimately picked up to series.

Bialik, who joined the show as a recurring foil for Parsons' Sheldon late in season three and was promoted to regular the following year, took to her blog to express her sadness with saying farewell to the show.

"This is hard. I love coming to work and pretending to be Amy. She’s a riot. She’s me, and I am her. And soon she will not be mine to create," the actress wrote. "It’s very sad. I fear it’s going to be very hard to not cry every day for the next 23 episodes! But, as a cast, we love bringing joy to our viewers and we will continue to do that to the best of our collective ability."

For his part, co-creator Bill Prady expressed how much he'd treasure his Big Bang Theory "family" in a heartfelt post on Twitter.

"There are many ways to look at the dozen years of Big Bang Theory as we draw to a close, but for me it will be the family that gathered each week to create a true labor of love. I will treasure my Big Bang family to the end of my days," he wrote.

Prady executive produces alongside Lorre and former showrunner Steve Molaro. The final season will again be steered by showrunner Steve Holland as Molaro focuses on Big Bang Theory prequel Young Sheldon, which counts Parsons as an exec producer (and voiceover actor). Stars Johnny Galecki, Simon Helberg and Rauch have not yet commented. (We'll update this post when/if they do.)

The Big Bang Theory's final season returns Monday, Sept. 24, as Sheldon and Amy honeymoon in New York and guest stars Teller and Kathy Bates return alongside Neil deGrasse Tyson.