Additive Manufacturing (AM), also known as 3-D printing, is an emerging advanced manufacturing technology that has the potential to revolutionize product realization on a global scale, dramatically shortening the concept-development/qualification-deployment cycle. AM technologies for polymers, ceramics, and metals are now being exploited for low-volume production of specialty and hard-to-find parts in such widely varied industries as aerospace, motorsports, orthopedic implants, and dentistry. It is becoming increasingly clear that AM may be an attractive solution for modernizing NNSA’s manufacturing infrastructure — reducing the time to product for nuclear weapons components, decreasing manufacturing footprint, and decreasing waste. Recently, NNSA has launched an AM initiative to apply AM to near-term deliverables while continuing to develop this technology for longer term rewards. NNSA laboratories, production plants, and university partners are developing this promising technology. R&D is ongoing to explore the range of materials and component types that are amenable to AM, broadening the material diversity, tailoring commercial AM machines, inventing new AM processes, and understanding how novel AM-created structures behave over a wide range of dynamic conditions. Building on our base of capabilities developed within the Stockpile Stewardship Program, we are using modeling and simulation to understand and predictively control the connection between additive processes, material structure, material properties, and component performance. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.