This paper summarizes the research of the CIS Team at NREL in three major areas: absorber deposition; understanding the role of chemical bath deposited (CBD) CdS in CIS junctions; and in the development of devices without CdS. Low cost, scaleable processes chosen for absorber fabrication include sputtering, electrodeposition (ED), and close spaced sublimation (CSS). The interaction between the CBD and the CIS has been investigated and the results show that Cd might be instrumental in shaping the interface. We have also developed a process to fabricate a 13.5% efficiency ZnO/CulnGaSe(2) device without CdS or other buffer layers.