Button assemblies using curable foam shims are disclosed. A button assembly may include a housing, a button positioned within the housing, and a curable foam shim positioned within the housing, the foam shim transformable between a compressible state having a first thickness, to a rigid state having a second thickness smaller than the first thickness. In this manner, the foam shim can be used to adaptively fill the interior of a button assembly by adapting to the dimensions of various components within the button assembly. In another example, a button assembly is formed using a foam shim by curing from a first state having a first thickness to a second state having a second thickness greater than the first thickness. In this manner, the foam shim can be used to adaptively fill the interior of a button assembly by adapting to the dimensions of various components within the button assembly.