Nicole Munger scored 20 points for Michigan (21-11), which fumbled away an inbounds pass and a chance for the win with 1.5 seconds left. Naz Hillmon had 16.
The Wolverines almost ruined Maryland's milestone moment by pushing the regular-season conference champs to the wire. Hillmon's putback with 21.8 seconds left gave Michigan a 72-71 lead.
Instead, Charles was fouled coming out of the timeout and made both foul shots to give Maryland the lead.
The Wolverines had two chances to win but Shakira Austin swatted Amy Dilk's short runner out of bound and Hallie Thome lost the ball coming out of another timeout.
Michigan: Nobody wants to see Michigan in the NCAA Tournament. The Wolverines are playing with confidence, having fun and winning games. And it's made a difference. On Jan. 28, the Wolverines were 10th in the conference standings. Since then, they climbed six spots to earn a double-bye, beat Wisconsin in overtime to reach their first semifinal since 2001 and nearly pulled off a stunner against the Terps.
Maryland: The Terps certainly were out of sync. They had seven turnovers in the second quarter, nine in the first half and trailed at halftime for only the sixth time this season. But they got things together in the nick of time. It could hurt their argument for a No. 2 seed — especially if they struggle again Sunday.
Michigan: Heads home to find out where it plays in the postseason