"Michael has been outstanding since joining us from Tottenham and it is great to know he will be a part of this squad for many years to come."
Carrick joined United from Tottenham two years ago for £14million and follows Rio Ferdinand this week in pledging his long-term future to the club.
Ferdinand signed a new five-year deal and is being backed as an England captain in waiting.
Carrick is pleased to have the matter finally sorted out before the showdown in Russia.
He said: "Manchester United is a fantastic club and it is a pleasure to be part of this great squad.
"I believe this team will be together for many years to come.
"To win back-to-back titles in my first two seasons at the club is a dream come true."