Race stewards said Schumacher "illegitimately impeded" Barrichello on the 66th lap Sunday. Schumacher appeared to try to force Barrichello into a concrete pit wall as the two vied for 10th place.
The seven-time world champion was penalized 10 places on the grid for the next race, the Belgian GP on Aug. 29.
Schumacher reviewed what happened and agrees with the stewards. He said he did not intend to endanger the Williams driver and was "sorry" if Barrichello had that impression.
"Yesterday, directly after the race, I was still in the heat of the moment, but after seeing the scene against Rubens again and I have to say the stewards were right with their assessment: The maneuver was too hard," Schumacher said on his website.
Schumacher is driving for Mercedes driver in his first season racing following a three-year retirement. The German is ninth in the standings, with his best finishes fourth at Barcelona and Istanbul. He was 11th in Hungary.
Mercedes boss Ross Brawn said the team accepted the penalty but did not necessarily agree with the stewards.
"It's been a tough weekend but we will go away, lick our wounds and come back stronger at the next few races," Brawn said.