The incident relates to 13th over of the Mumbai innings when Smith, while running between the wickets, collided with fast bowler James Faulnker.
Match referee found that it was deliberate on the part of the West Indies batsman.
"Smith admitted to the Level 1 offence (Article 2.1.8) of conduct contrary to the spirit of the game," an IPL release said.
For Level 1 breaches of the IPL Code of Conduct, the Match Referee's decision is final and binding.