Phase change memory cell structures and methods are described herein. A number of methods of forming a phase change memory cell structure include forming a dielectric stack structure on a first electrode, wherein forming the dielectric stack structure includes creating a second region between a first region and a third region of the dielectric stack structure, the second region having a thermal conductivity different than a thermal conductivity of the first region and different than a thermal conductivity of the third region of the dielectric stack. One or more embodiments include forming a via through the first, second, and third regions of the dielectric stack structure, depositing a phase change material in the via, and forming a second electrode on the phase change material.