This is dependent upon your discretion and the design of the bunk bed itself. Some of these beds have safer stepping systems wrapped around the structure of the beds, allowing smaller children to traverse the space between the floor and top bunk with relative safety. Ladder systems aren’t inordinately dangerous in and of themselves, but the products typically do suggest buying for children over the age of 6. The weight capacity for the top bunks on these beds is typically around 200 pounds, meaning it will work for most children right on through adolescence.