Custer, a 2014 point guard from Blue Valley Northwest in Overland Park, Kansas, committed last November.
"They are going to be my family for four years," Custer told Scout.com in 2012. "We knew in our heart that was the best place for me to go."
The 6-foot-1, 190-pound Custer is a three-star prospect who has started every game since his freshman season for the Huskies, who have gone 71-4 in that span with three trips to the state finals, the last two being championships. Already, Custer holds the school record in points (1,190), assists and steals.
"He's a really good player," Huskies head coach Ed Fritz said. "I think the thing people at Iowa State will like is he's a regular kid, easy-going down-to-earth, happy kid. Loves to play and compete."
The Huskies went 25-0 last season and enter this year No. 18 in the USA Today rankings.
Fritz has coached Custer since the latter was in the third grade.
"He was good enough to play as a freshman and keeps on getting better," Fritz said.
"A lot of people from Kansas say he reminds them of Kirk Hinrich," Fritz said. "Unbelievably fast with the ball, does an unbelievable job advancing the ball, he can go 100 miles an hour with the ball and stop on the dime and go up for a jump shot while everybody's still backing up. He's so skilled. He just doesn't look the part, a little white kid. He can play, keeps proving people wrong."
Custer was a first-team all-state Class 6A pick in 2012 and 2013. He averaged 22.2 points, 2.1 steals and 5.3 assists with a 59-39-80 percentage line from the field, three-point and teh foul line as a junior.
Custer chose Iowa State over Kansas State, Oklahoma State and Oklahoma.
The Cyclones do not have any other commitments from high school prospects, though they are in the running for Rashad Vaughn, who will take his official visit Nov. 15-17, and will have the services of transfer Jameel McKay beginning in spring 2015.