Maci, who found fame on MTV's 16 & Pregnant and Teen Mom, announced her happy news on Twitter this evening (31 May).
The mum-of-three revealed: "Mr. Maverick Reed has officially made his debut & completed our family. So much love, so many blessings!"
In February, Maci revealed that she was pregnant with a little boy, telling fans on Instagram: "Baby boy coming soon! #lastbutnotleast."
Maverick is Maci's second child with fiancé Taylor McKinney, as they welcomed daughter Jayde into the world last June.
The US reality star's pregnancy with her eldest child, her son Bentley, was featured on 16 & Pregnant, along with her rocky relationship with his father, Ryan Edwards. Bentley is now eight years old.
In January of this year, Maci and Taylor got engaged.
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