The last couple of years have been ambitious ones for the Metropolitan Museum of Art. Perhaps too ambitious.

Now the museum is acknowledging that it may have overreached and is facing a deficit of $10 million this year, which officials said would almost certainly balloon to as much as $40 million if the Met does not change course and scale back.

The museum opened its new Met Breuer space in the Whitney’s former building on Madison Avenue, which will cost $17 million each year to run. It selected an architect, David Chipperfield, to design its new $600 million wing for modern and contemporary art. And it reached a settlement in part of a long-running legal challenge to its admissions policy, agreeing to call its $25 full-admission charge “suggested” instead of “recommended.”

So the museum is changing course. On Thursday, it announced a 24-month financial restructuring that it said was likely to include staff reductions, slower construction of its new wing and reduced programming.