April 21, 2018 07:41 PM

Happy birthday, Billy Kimmel!

Jimmy Kimmel celebrated his son’s first birthday on Instagram Saturday with a sweet post to his youngest child and a touching thank you to the doctors and nurses who helped save Billy’s life.

“A yr ago today, God gave us this tough little boy. Today, we thank the nurses & doctors at @CedarsSinai & @ChildrensLA who saved his life & those who shared thoughts & prayers,” the Jimmy Kimmel Live! host wrote along with an adorable photo of Billy wearing a birthday hat and red bow tie.

“We cannot stay quiet. Please wish Billy happy birthday by REGISTERING TO VOTE! vote.gov,” the father of four added.

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RELATED: A Comprehensive Guide to All the Times Jimmy Kimmel Has Gotten Political

Kimmel and his wife Molly McNearney overcame a heart-wrenching few months when their baby son underwent two heart surgeries after he was born with the congenital heart condition, tetralogy of Fallot with pulmonary atresia.

In May, the 2018 Oscars host revealed during a tearful address that Billy had open heart surgery at 3 days old as a result of his son’s “pulmonary valve [being] completely blocked and a hole in the wall between the left and right sides of his heart.”

Then, Billy had a second surgery at the Children’s Hospital Los Angeles in December at 7 months old. (Kimmel and McNearney also share 3-year-old daughter, Jane. He also has two older children – Kevin and Katie – from a previous relationship.)

Jimmy Kimmel/Instagram

Since sharing his son’s heart condition and recovery, Kimmel has emerged as a prevalent political voice in the late-night world and has become an ardent advocate for universal health care coverage.

He also has used his ABC show as a platform to speak out on other issues, including gun control and the controversies surrounding the Alabama Special Election.

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