Head Coach Dejan Udovicic announced the team July 7 on the deck of the USS Midway in San Diego.
Hallock led the Wolverines to become CIF- Southern Section Division I champions in 2013 and 2014 and was named the Co-Division I Player of the Year in 2014 as well. Over his last high school season, Hallock scored 97 goals and contributed 86 assists despite missing three weeks of play due to a hand injury.
In the 2015 FINA Intercontinental Tournament last April, Hallock had four goals and two assists, helping Team USA take third place.
Hallock will be the youngest member of the team, which will be lead by attacker Tony Azevedo who is the first U.S water polo player to compete in five Olympic Games. The team is currently ranked sixth, coming off a win at the Pan American Games and finishing seventh at the world championships in their 2015 season. Team USA finished eighth at the 2012 London Olympic Games.
The team will play their first match Aug. 6 against defending champion Croatia.