Package structures and methods for forming the same are provided. A package structure includes a semiconductor die. The semiconductor die includes a passivation layer over a semiconductor substrate. The semiconductor die also includes a conductive pad in the passivation layer. The passivation layer partially exposes a top surface of the conductive pad. The package structure also includes an encapsulation layer surrounding the semiconductor die. The package structure further includes a dielectric layer covering the semiconductor die and the encapsulation layer. In addition, the package structure includes a redistribution layer covering the dielectric layer. The redistribution layer extends in the dielectric layer to be physically connected to the top surface of the conductive pad.