NBA president of basketball operations Rod Thorn made the announcement Sunday.
The hit occurred with 1:28 remaining in the third quarter of the Warriors' 123-110 victory over the Mavericks Saturday.
Livingston was serving his suspension Sunday during the Warriors game against the San Antonio Spurs.
Livingston was called for a flagrant foul when video review showed him punching Nowitzki in the groin area while the big German was backing in for a shot.
Livingston said after the game that the play looked worse than it was and that it was just bad timing.