Cameron Monaghan is joining Emmy Rossum in leaving Shameless. Monaghan bid his co-stars farewell in a long Instagram post and thanked fans for their support.

"I have been a series regular on this show for roughly ten years," Monaghan wrote on Instagram, alongside a gallery of photos with his Shameless co-stars. "I was the tender age of 15 when we shot the pilot, and I came of age in so many ways, both legally and personally. I was very lucky to mature and grow with this show. Experiencing so many firsts, maturing as an actor, a professional, and a human. In the process gaining friends, family, and the best coworkers a very lucky actor could ask for, and for this I can be nothing but gracious."

"All good things come to an end," Monaghan, who plays Ian Gallagher, continued. "An old cliché, but one that rings true with a sincerity and clarity especially in moments like these. Everything ends."

Monaghan went on to say that the next episode of Shameless is his last. He knew he was leaving since last year, but waited until now to announce in order to keep his departure a surprise.

"The next episode will be my last. I have known since last year, but I didn’t want to give it away too early as I wanted this season to be a surprise for the audience, allowing them to experience Ian’s unsure journey with his character," Monaghan continued. "This role has been a joy to inhabit, a wild and special ride, and I’d like to thank #Shameless as well as you, the viewers, for being there with him."

In the end, Monaghan wrote, "Goodbye, Ian Clayton Gallagher. We’ll meet again?"

Monaghan, 25, has been on Shameless since the beginning. In 2015, he earned a Critics' Choice Television Award nomination. He also stars as Jerome and Jeremiah Valeska on Fox's Batman prequel series Gotham.

Monaghan is the second major Shameless star to announce plans to leave in three months. In August, Rossum surprised fans by announcing season nine would be her last on Shameless.

"Until Shameless came into my life 8 years ago, I led that kind of transient wonderful life of an actor. And I never realized how much I actually craved the kind of continuity that this show has given me," Rossum wrote on Facebook in August. "See, in real life, unlike Fiona, I'm an only child. I never had a big family. Being ensconced in that messy Gallagher family love is something I'd always dreamed of."

New episodes of Shameless air on Sundays at 9 p.m. ET.

Photo Credit: Showtime