Missy Meharg's squad will welcome two top-10 players as part of the class.
The forward's decision leaves the Terps' frontcourt depth thin.
Jarrett is the Terps' first five-star recruit since Damian Prince in 2014.
"This group is a great continuation of the culture we're building at Maryland."
McDougle's commitment gives the Terps the No. 38 recruiting class in the country.
Boone is the Terps' first four-star recruit in their 2020 class.
Jackson is the Terps' 10th commitment for their 2020 recruiting class.
Battle's commit comes just one day after the Terps landed offensive tackle Santana Saunders.