Belichick apologized in a statement distributed by the team Wednesday afternoon.
"It was inappropriate for me to contact the official. I take responsibility for what happened. I accept the discipline and I apologize for the incident Sunday night in Baltimore," he said.
Belichick explained his intentions Monday. In part, he said, "I was trying to get the official’s attention to get an explanation on [the end of the game], and in no way was I ever trying to do anything other than that."
Last week, the NFL instructed teams that it would enforce rules requiring respect for on-field officials.
Belichick is the fourth coach fined this week. Denver head coach John Fox and defensive coordinator Jack Del Rio were fined $30,000 and $25,000, respectively, on Monday for abuse of officials in Week 2. Washington offensive coordinator Kyle Shanahan was also fined $25,000 for verbal abuse in Week 3.