has revealed that his son Billy had his third (and hopefully last) open heart surgery over Memorial Day weekend. “We went into this experience with a lot of optimism and nearly as much fear and came out with a new valve inside a happy, healthy kid,” the ABC late-night host , captioning a photo of Billy smiling in what looks like a hospital bed. Kimmel went on to praise the doctors, nurses and staff at Children’s Hospital Los Angeles, where Billy was treated.

“We hope you never need CHLA, but if you do – know that they help families regardless of their ability to pay, thanks largely to the Affordable Care Act (another salute to the late Senator John McCain), generous donations from companies like Disney, which I am proud to work for and especially from generous people like you,” Kimmel wrote. He also thanked his friends, family and even strangers for their support for Billy. “Thank you to my wife Molly for being stronger than is reasonable for any Mom to be and Billy, you are the toughest (and funniest) 7 year-old we know,” Kimmel added.

He went on to urge people to support Children’s Hospital L.A. and their local children’s hospitals.

Kimmel has previously been outspoken about Billy’s health issues. Shortly after Billy was born, Kimmel spoke about Billy’s congenital heart defect and his then-baby’s need to have open-heart surgery, again at Children’s Hospital, at just three days old. The procedure went well but inspired Kimmel to advocate for healt.