Combined heat and power (CHP) technology holds enormous potential to improve the nation’s energy security and reduce greenhouse gas (GHG) emissions. This paper describes DOE’s success in building a solid foundation for a robust CHP marketplace over the period of a decade, as well as what can and must be done to tap CHP’s full potential. In summary, this paper provides an overview of CHP, DOE's CHP program, accomplishments, progress, technology R&D, marketplace transformation, partnerships, strategies, and future goals.