Dominant performances from Katie Benzan and Ashley Owusu brought the Terps back into the win column.
Mikesell scored a career-high 33 points against her former team and went 5-for-5 from three.
Briggs suffered a season-ending injury after competing in 14 games for Florida, but will join the Terps for the 2022-23 season.
With the loss, the Terps' 31-game home winning streak came to an ugly end.
In the Terps' ever-changing starting five, Bibby's success in the two forward spots has been a constant.
Miller and Owusu combined for 44 points in Miller's first start of the season.
The Terps lost to the Hoosiers for the first time in program history.
The Terps are hoping Miller builds off her first game back from injury against Coppin State on Dec. 21.
The Terps struggled offensively against the Gamecocks who pulled down 61 rebounds.
Reese leads the team in personal fouls with 27, keeping her off the court with an average of 23.3 minutes per game.