According to People magazine, the 18 year-old sisters want to find a buyer for their over 6,000-square-foot penthouse.
The twins bought the penthouse a few months prior to their acceptance to New York University.
A representative for the girls has denied rumours that the sale of the apartment is because of Mary-Kate’s recent health problems.
"It’s absolutely not true," he told the magazine. "She will continue to be enrolled in NYU in the fall. They both will continue to be enrolled in the fall."
"Mary-Kate is doing OK and is focused on finishing up the school year."