The alkali metal thermal to electric converter (AMTEC) technology has grown tremendously over the past 10 years. Innovations such as wick pumping, remote condensing and multi-tube cells have advanced the technology substantially. New innovations have been identified that will further advance the technology. The internal selfheat pipe (ISHP), for example, is predicted to increase the efficiency by a full 3 points. Proof-of-principle tests have been completed, and prototype testing is about to begin. This paper will present the design concept and available test data for this new AMTEC innovation.