Visitors to National 9/11 Memorial and Museum could pay as much as $25 for admission.

While the exact entrance price has yet to be set, museum officials have agreed to charge guests a flat rate, as opposed to a suggested donation used by other area museums, the New York Daily News reports.

Charging admission to the museum, located at Ground Zero, has stirred controversy, especially among those who lost family members in the terrorist attacks.

A relative of a fallen firefighter called the planned fee “absolutely disrespectful,” telling the Daily News, "It’s not a business — it’s a memorial.”

While the 9/11 museum has yet to open, the memorial portion of the site, which includes the reflection pools where the Twin Towers once stood, has been open to the public since 2011.

Organizers recently started charging a $2 service fee for reservations made online to support operational costs. Passes obtained in person for same-day visits remain free.

Set to open in April, the 9/11 museum is expect to draw 2.5 million people annually.