On March 11, 2013, Josh and Anna Duggar announced on the Today Show, then via Josh's Twitter, that they were expecting their third child, due June 7, 2013. Josh commented on the pregnancy, saying: "It is very exciting. It's fun for Michael and Mackynzie being so close in age and this baby will be, too. We feel very blessed and happy.". Anna had recently taken a negative pregnancy test, and commented: "I thought for sure I was pregnant and so I was a little disappointed. But two weeks later, I found out I was pregnant. I got sick overseas and then when I returned home, I was then into the morning sickness. But now, I have more energy than I ever had before.".
Josh and Anna broke the news to Josh's family with the assistance of Josh's cousin, Amy, by preparing a family meal of baby carrots, baby corn, and baby cherry tomatoes. Josh's father, Jim Bob, commented saying: "Josh and Anna are great parents. It is neat to see their family expanding.". Their pregnancy announcement is featured on the 19 Kids and Counting episode "Baby on the Way".
On April 1, 2013, Josh and Anna announced that they were having a boy. The couple found out through a surprise planned by their sound man, Jim, who had the family's friend, Pastor Howard, relay the information in a church service at Restoration Church of Northwest Arkansas, in Fayetteville, Arkansas. Their gender reveal is featured on the 19 Kids and Counting episode "Baby Gender Reveal & the Final Weigh In".
His birth was announced on June 7, 2013. Marcus Anthony Duggar was born at 11:32 a.m. on June 2, 2013, at the home of a nearby midwife in Fort Smith, Arkansas. He weighed 9 pounds and 3 ounces, and was 21 inches long. Anna gave birth to Marcus in the bathtub. Josh's sisters Jana and Jill were there to assist as well. His birth is featured on the 19 Kids and Counting episode "GrandDuggar Makes 3!".
"Mackynzie and Michael are thrilled to welcome a little brother, and we are so thankful that mom and baby are well. We are blessed to have our family close as we celebrate this gift from God!", Josh said in a statement to the Today Show. "It's not really about the number of children you have, but how well you are doing with the children that God has given you. We're really just going to take it one at a time. I don't think you can say we're going to set out and say we're going to have five kids or four or three. We have no control over that. God has the control.".
In June 2013, only weeks after Marcus was born, he and his family moved to Oxon Hill, Maryland, so his father could start a new job working for the Family Research Council, in Washington, D.C..
In the wake of Josh's molestation scandal, the family had to move back to Arkansas. The family was seen moving out of their Oxon Hill, Maryland home on June 9, 2015.
Marcus is described as enthusiastic, energetic, nature-loving, adventurous, and having an amazing memory.
Along with his siblings, Marcus is currently being homeschooled.
Marcus is frequently featured on the TLC show Counting On.