The Lori Bed does not include a mattress. You can choose any mattress that works best for you and your family but just be sure to follow the below guidelines: Maximum thickness of 12". Anything thicker will run the risk of the bed not closing properly into the cabinet. Go light with your mattress! Recommended maximum weight of 80lb for Queen and 50lb for Twin. Since you will manually operate this bed, keep in mind that even an extra 10-20lbs on your mattress can make a big difference in how heavy it will feel. Therefore, the lighter the better!