Zac Hanson and wife Kathryn welcome baby number FIVE as they announce the birth of their son Quincy

Zac Hanson is a father once again.

The youngest brother of the ’90s boy band Hanson welcomed his fifth child Sunday, March 7 with wife Kathryn.

He took to Instagram to announce the birth of their son Quincy Joseph Thoreau, while paying tribute to the mother of his children in a belated International Women’s Day post.

New addition: Zac Hanson took to Instagram to announce the birth of their son Quincy Joseph Thoreau, while paying tribute to the mother of his children in a belated International Women’s Day post

The 35-year-old wrote: ‘I am a little late, but I celebrated #internationalwomensday the best way I know how. Marveling at the superpower women are uniquely gifted… 

‘As well as freaking out over the fact that I am now responsible to help raise another person. Quincy Joseph Thoreau Hanson. Born 3/7/21’

He included a black-and-white photo of Kathryn holding the newborn, as well as one of himself jokingly screaming in terror with his baby boy in his arms.

Zac and Kathryn tied the knot in June of 2006, and they also share sons John Ira Shepherd, 12, George Abraham Walker, seven, daughters Junia Rosa Ruth, 10, and Mary Lucille Diana, four.

Women's day gift: The 35-year-old wrote: 'I am a little late, but I celebrated #internationalwomensday the best way I know how. Marveling at the superpower women are uniquely gifted...'

Women’s day gift: The 35-year-old wrote: ‘I am a little late, but I celebrated #internationalwomensday the best way I know how. Marveling at the superpower women are uniquely gifted…’

Baby boy: He added: 'As well as freaking out over the fact that I am now responsible to help raise another person. Quincy Joseph Thoreau Hanson. Born 3/7/21'

Baby boy: He added: ‘As well as freaking out over the fact that I am now responsible to help raise another person. Quincy Joseph Thoreau Hanson. Born 3/7/21’

He announced the pregnancy news in January, telling People: ‘We’re so happy and thankful for the things 2020 got right, especially this little guy coming in March! Here’s to fresh starts and new beginnings.’

Kathryn later told Us Weekly that they’re done growing their family with the newest addition: ‘We feel really fulfilled and complete with five!’

She added: ‘The biggest difference this time around has been how much more aware and excited our kids are about the new baby now that they’re older.’ 

Happy family: Zac and Kathryn tied the knot in June of 2006, and they also share sons John Ira Shepherd, 12, George Abraham Walker, seven, daughters Junia Rosa Ruth, 10, and Mary Lucille Diana, four

Happy family: Zac and Kathryn tied the knot in June of 2006, and they also share sons John Ira Shepherd, 12, George Abraham Walker, seven, daughters Junia Rosa Ruth, 10, and Mary Lucille Diana, four

Fresh starts: He announced the pregnancy news in January, telling People: 'We're so happy and thankful for the things 2020 got right, especially this little guy coming in March! Here's to fresh starts and new beginnings'

Fresh starts: He announced the pregnancy news in January, telling People: ‘We’re so happy and thankful for the things 2020 got right, especially this little guy coming in March! Here’s to fresh starts and new beginnings’

Big family: It comes after brother Taylor Hanson, 37, welcomed his seventh child in December, as Isaac, 40, has fathered three of his own (pictured in July, 2019)

Big family: It comes after brother Taylor Hanson, 37, welcomed his seventh child in December, as Isaac, 40, has fathered three of his own (pictured in July, 2019)

It comes after brother Taylor Hanson, 37, welcomed his seventh child in December, as Isaac, 40, has fathered three of his own. 

Zac and his brothers have been performing together since 1992, when he was six years old, dropping their most memorable hit MMMBop in 1997.

They dropped their compilation album Perennial — A Hanson Net Collection back in November, telling E! News: ‘There’s no way we can properly clarify how appreciative we are over these 20 years of [our fans] because life—there’s a lot of ups and downs.

‘2020 is a great example of that. There’s a lot of curveballs thrown at you throughout your life, and music has the power to heal hearts and bring people together.’

Boy band: Zac and his brothers have been performing together since 1992, when he was six years old, dropping their most memorable hit MMMBop in 1997

Boy band: Zac and his brothers have been performing together since 1992, when he was six years old, dropping their most memorable hit MMMBop in 1997