Kacie, 28, has given birth to a baby boy, her first child with husband Rusty Gaston.
Kacie, who took Rusty's surname when they wed, told her Twitter followers on Monday she was going into labor.
"It's LABOR DAY! The kind where your water breaks!! Baby Ranger is on his way!" Kacie tweeted.
She and Rusty welcomed their son, Ranger Gaston, on Tuesday at 5:26PM.
"Hello world! Ranger Gaston |9-8-15|5:26|4lb14oz|17in| He's perfectly healthy and happy! @rustygaston and I can't believe what a blessing God has given us! 'For You created my inmost being; You knit me together in my mother's womb. I praise you because I am beautifully and wonderfully made.' Psalm 139:13-14a," Kacie captioned a photo of her newborn baby on Instagram Wednesday.
Kacie told E! News she's doing well and the couple is "so blessed to have such an amazing son."
"He's absolutely perfect and has stolen our hearts. We can't wait to see what God has in store for him," the former reality TV star told the website. "Labor went amazing. Rusty was such an amazing supporter and I couldn't have done it without our amazing doctors and nurses. It's such a miracle what your body can do."
Kacie announced she was pregnant and expecting a boy in June. She randomly met Rusty while at a restaurant with friends in December 2012. The music executive popped the question in February 2014, and the couple got married in May of that year in Nashville, TN.