For generations, one of the best things about New York City’s Metropolitan Museum of Art was the admission—while the place wasn’t free, it had a “suggested entry fee” that most visitors simply never paid.

Soon, however, due to a proposed policy change that appears to be gaining momentum, the taxpayer-supported museum may begin to charge admission for visitors who do not live in New York City.

According to a recent article in the New York Times, officials from both the Met and the city have spent the better part of a year discussing the controversial policy change as a way to alleviate the museum’s $15-million budget deficit. The move was back in the news this week when NYC Mayor Bill DeBlasio endorsed the plan and noted that it would be “fair” to impose a fee that specifically applied to “non-city residents.” It makes sense: New York City residents already help fund the museum through paying their taxes.

But the Met’s reliance on those “non-city residents” complicates the issue—the museum draws 63 percent of its annual visitors from outside of New York State.

For visitors, this change could result in a significant hit to their travel budgets. Currently, the Met’s suggested admission fee for visitors over the age of 12 is $25. Under the new rules, a middle-aged couple with two teenage kids visiting the museum from out of state would be on the hook for $100.

The Times article noted that suggested fees generated about $39 million in the 2016 fiscal year, which made up 13 percent of the museum’s overall revenue. Museum officials interviewed for that piece said a mandatory fee would likely generate tens of millions of dollars more per year. However, the same museum officials worried aloud that, as a result of the potential increased revenue from ticket sales, the city might redirect some of the $26 million in funding that it gives the museum annually to other arts groups.

This controversy is far from decided. In addition to figuring out how ticket revenue would impact city money, museum and city officials will need to consider other outstanding issues, including how to charge people who work in the city but live elsewhere.

As of now, there is no indication when these decisions will be made.

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