The 9/11 Memorial and Museum’s first full year of operation ended in the red, with costs outstripping revenues by $25.2 million, The Post has learned.

The private nonprofit foundation, chaired by former Mayor Mike Bloomberg, racked up $108 million in expenses but took in only $87.3 million, just-filed 2015 tax records show.

The negative bottom line stems largely from a drop in revenues as government grants used to construct the museum were spent.

The foundation received only $17 million in grants and contributions in 2015 but raked in $61.8 million from the sale of tickets, tours, memberships and souvenirs.

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The memorial, where twin pools mark the fallen Twin Towers, is open to the public at no charge, but the museum charges $24 admission, or $15 to $18 for seniors, veterans, students and youths. Close to 6 million people have visited the museum.

The museum’s gift shop, which sparked controversy for selling 9/11-themed T-shirts, jewelry and dishware — including a since-discontinued cheese plate — took in $5 million, the records show.

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