After a week off from hosting duties on his late night show, Jimmy Kimmel returned on Monday with a new co-host to help deliver the opening monologue: Billy, Kimmel's infant son, who underwent heart surgery last week.

"Look, he's fine!" Kimmel announced, to cheers from the audience.

The saga of Billy's medical problems has been a pivotal issue for Kimmel since the boy was born with a heart defect last year, prompting the talk show host to become an outspoken advocate for healthcare, and particularly the Affordable Care Act. Last night, a tearful Kimmel made yet another speech on behalf of children's healthcare, this time lambasting Congress for failing to pass funding for the Children's Health Insurance Program (CHIP) that covers kids whose parents don't qualify for Medicaid or comprehensive coverage through their jobs.

"Tell them to take a break from tax cuts for a minute and fully fund CHIP immediately," Kimmel said, urging viewers to call their representatives. Watch the full segment above.