The program covers about 9 million children whose parents usually earn too much to qualify for Medicaid, but not enough to afford private health coverage. More than a million lower-income children are at risk of losing their health insurance next year if Congress doesn't act soon.
Kimmel said CHIP is "not a partisan thing," noting that Democrats and Republicans "overwhelmingly" supported it until now.
The program has become a "bargaining chip," the ABC host said, and is "on the back-burner while they work out their new tax plans."
"Which means parents of children with cancer and diabetes and heart problems are about to get letters saying their coverage could be cut off next month," he said. "Merry Christmas, right?"
Some states are already starting to run out of funds -- and a few have begun notifying parents that benefits may end in coming months.
Kimmel said he's had enough.
"What could be more disgusting than putting a tax cut that mostly goes to rich people ahead of the lives of children?" he asked.
"If these were potato chips they were taking away from us, we would be marching on Washington with pitchforks and spears right now," he said.
The host told his audience that he and Billy want them to call congress and tell their representatives to fund CHIP now.
Kimmel revealed in May in an emotional monologue that his son needed heart surgery a few days after he was born.