If you purchase a door that’s pre-hung or mounted onto a frame already (with a jamb and threshold), it can cost up to $200 more to install. As the name implies, your door comes already hung on a frame with hardware and hinges. Doors that aren’t pre-hung are known as slab doors and do not include a frame, hardware, hinges, or a knob. They offer more design flexibility and are much more cost-effective than pre-hung doors. You may save money on entry door installation costs if you only need a door replacement and not the door and frame combination. Yet, even though a slab door is cheaper upfront, you may spend more in the end when you add up hardware costs on top of the door. Additionally, a slab door is typically more expensive to install than a pre-hung door. Upfront costs for installing a pre-hung door may save you money on installation. Putting in a pre-hung door can be up to half the cost of installing a slab door.