Methods of forming and structures of packages are discussed herein. In an embodiment, a method includes forming a back side redistribution structure, and after forming the back side redistribution structure, adhering a first integrated circuit die to the back side redistribution structure. The method further includes encapsulating the first integrated circuit die on the back side redistribution structure with an encapsulant, forming a front side redistribution structure on the encapsulant, and electrically coupling a second integrated circuit die to the first integrated circuit die. The second integrated circuit die is electrically coupled to the first integrated circuit die through first external electrical connectors mechanically attached to the front side redistribution structure.