The museum is now closed on Mondays, except on holidays that fall on a Monday.
Also on July 1, the museum's opening time will be changed to 10 a.m., from the current 9:30 a.m.
The changes also apply to The Cloisters, the Met's museum of medieval art and architecture in Fort Tryon Park in northern Manhattan.
Museum Director Thomas Campbell said the decision was made to make the Met "accessible whenever visitors have the urge to experience this great museum."
The Met had a record 6.28 million visitors last year.
The museum made the announcement on Thursday.