The host had taken a week off due to his son Billy's second heart surgery, with celeb pals Chris Pratt, Tracee Ellis Ross, Neil Patrick Harris, and Melissa McCarthy helping to fill in. "But look he's fine everybody, he may have pooped but he's fine", he said during the emotional appearance.
He urged his viewers to call their congressmen to #FundCHIPNow.
Together with his son Billy, Kimmel made a plea for the Children's Health Insurance Program.
The program covers some nine million American children whose parents don't qualify for Medicaid, but don't have access to affordable healthcare via group insurance.
Kimmel said he's had enough.
According to Mr Kimmel, the bill has historically been a nonpartisan issue, but Congress members have begun using it as a bargaining chip to attempt to pass their tax plan.
Jimmy continued, "Parents of children with cancer, diabetes and heart problems are about to get letters saying their coverage could be cut off next month". "This is literally a life and death program for American kids". Imagine getting that letter, not knowing if you'll be able to afford to save your children's life. This is not a hypothetical; about 2 million CHIP kids have serious chronic conditions.
He added that it was "disgusting" that Congress is putting tax cuts for the richest ahead of the children's health. "Billy is doing great, by the way". "They say he's probably on track to win at least a bronze medal in the Olympics in 2036".
Actually, it's not that hard to believe considering everything Kimmel has seen his son go through over the past few months.
While holding onto his son, Jimmy asked viewers to call House and Senate phone lines [202-225-3121] this week and demand CHIP funding before it's too late.