The punishment was levied on Monday.
The incident occurred late in the first quarter of Minnesota's 103-82 loss to Miami on Saturday. Brewer was jockeying for rebounding position with Heat star LeBron James. After James bumped Brewer off the block, Brewer flailed his arms and thrust his body toward the free-throw line to act like he'd been pushed hard.
Brewer was warned by the NBA last month for flopping. The league instituted a crackdown on the practice prior to last season.
He's only the second player to receive a fine as James Harden was fined last month.