Jennifer Esposito is engaged to longtime boyfriend Louis Dowler.
"Oh, P.S. Announcement: Jennifer just got engaged," Couric said.
"I'm thrilled, " the Brooklyn native added, showing off her diamond ring. "He's lovely."
Esposito said she's already chosen a date for the nuptials, but didn't give away much in terms of details. However, she did share that Dowler works with her in her gluten-free bakery, Jennifer's Way, in New York.
"He wanted no part of it in the beginning," Esposito said. "He said, 'I don't know anything about a bakery.' I said, 'I don't know either, but we're gonna do this and I'm gonna do this and if you wanna see me that's where I'm gonna be on 10th Street.'
"So he actually lent me the rest of the money. This was all my money that I made this bakery on and he lent it to me, otherwise it wouldn't be there," she added.
It will be the second marriage for the actress: Esposito was married to "American Hustle" star
Esposito was also engaged to tennis player Mark Philippoussis in 2009.
Her new fiancé was linked to Oscar winner Kate Winslet in 2010, shortly after the actress split with her second husband, director Sam Mendes.
The "Samantha Who?" alum appeared on the talk show to promote her new book, "Jennifer's Way," in which she discusses her struggle with celiac disease.
"I was told everything from MS to IBS," she said when discussing all the different diagnoses she'd received before doctors were able to pin down celiac, an auto-immune disease that inhibits the digestion of gluten and ultimately causes malnutrition, among other issues.
The actress said she began to have panic attacks and was "house bound for a while" because of the toll it was taking on her central nervous system.
"I was searching for so long for answers and when you take gastric problems, back aches, sinus problems, a panic attack -- a doctor, understandably, is trying to put that in a puzzle and make that make sense," she said.
"Knowing now what I know about this disease, it makes sense to me because the small intestine basically is housing the serotonin in your brain and it causes depression if it's not balanced. So this is what was happening to me."
Esposito said her wake-up call came while on the set of "Samantha Who?" She recalled her knees giving out, skin problems and yellowing that she experienced, and "one day on set we were doing a scene and a tooth popped out of my mouth."
It was "frightening, and I have to tell you, infuriating," she said. Watch the full clip here.
After the show, Esposito thanked her host for letting her speak about the disease.
"A special thanks to Katie @KatieShow who was truly interested and gave me a platform to speak for many about this tricky disease. #celiac," she tweeted.
"So glad to have you on the show!" the host replied.