In real life, Baumann also runs a publishing house, designs book jackets and has just written a novel. And he's battling Crohn's disease.
"It's basically when your digestive system eats itself," he said, discussing the condition today in an interview that aired on "Good Morning America."
Crohn's causes inflammation of the digestive tract. Its symptoms include pain and diarrhea, and can lead to potentially life-threatening complications.
Other celebrities who suffer from Crohn's include the singer Anastacia and actress Shannen Doherty, who once said she didn't want discuss it. She feared talk of frequent bathroom breaks might affect how she was perceived.
ABC News' Nick Watt asked Baumann why he wanted to discuss his condition. "Well, I was thinking about the 14-year-old fan of the show. Going through the pain and not knowing what it is," the actor replied.
Baumann, 22, underwent surgery and lost 20 pounds. His dog, Oscar, weighs more than he does. "If you have a sense of humor, even when you're in pain, it helps. When I did my first fart after surgery it was like hearing Beethoven's Ninth," he said.
There's no cure for Crohn's, but Baumann said he has it under control.
And even though the actor plays a kid on TV, he's all grown up.
He married "Superbad" actress Aviva Farber, 28, last month in a secret ceremony in Malibu, Calif. "We're very democratic," he said of their relationship, adding, "But I bow to her wisdom."
So what's next for "The Secret Life of an American Teenager"?
"I think we've already done impregnation," he said. "But we meet so many fans who tell us their stories, which make us feel we haven't even touched the tip of the iceberg."