The 54-year-old “Today” co-host posted a sweet picture on Instagram with her boyfriend, 61, on Wednesday to commemorate the occasion.
“Yesterday marked 6 years with this incredible man. 6 years..2 children..2 new jobs...1 grateful heart,” Kotb wrote.
“Ps thank you @jolamathisen and #tyler .. if it weren’t for you two.. we never would have met on that night,” she added to her friends who set her up with Schiffman.
Kotb’s “Today” co-anchor Jenna Bush Hager commented on the post to say, “Congrats,” along with a heart emoji.
Schiffman and Kotb first met at an event in 2013. They didn’t go public about their relationship until 2015, according to People, and in 2016 they moved in together.
Kotb opened up about her relationship with Schiffman, a financier, back in 2015 after going public with their relationship.
She gushed over Schiffman on "Watch What Happens Live," hosted by Andy Cohen.
"You know, I met him a couple of years ago. He's the greatest guy ever," she said at the time.
A battle with breast cancer 10 years ago left Kotb unable to conceive and her two-year marriage to tennis coach Burzis Kanga fell apart a year after her recovery. The news anchor had all but given up on having a child.
"One of the things in my life I've always wanted was to be a mom," Kotb told People in 2017. "Sometimes in your life, things just don't work out for whatever reason, so you say, 'Well, I wasn't meant to have that.' But it was really hard to come to terms with it."
But then one day, Kotb decided she was going to be a mother. She asked Schiffman if he was open to adopting a baby and he was onboard immediately.
In May, Kotb revealed how quickly her life has changed as a mother of two.
“I just can’t believe how in a blink, life changes, and all of a sudden there are two babies in this house. I’m just overwhelmed with joy,” she told People at the time.
Fox News’ Sasha Savitsky, Andy Sahadeo and The Associated Press contributed to this report.