This paper provides a comprehensive review of the state-of-the-art in metal additive manufacturing (AM), also known as additive manufacturing (AM), direct digital manufacturing, free form fabrication, or 3D printing. AM has the potential to revolutionize global parts manufacturing and logistics by enabling distributed manufacturing and on-demand production, while reducing costs, energy consumption, and carbon footprint. The paper explores the material science, processes, and business considerations associated with achieving these benefits. It highlights the need for a paradigm shift to fully exploit the potential of AM, including advancements in process controls, sensors, and models, as well as metallurgy and mechanical properties. The paper also discusses the challenges in qualification and certification, and the business case for AM, emphasizing its potential to reduce costs and improve efficiency in small production lots. Finally, it addresses the environmental impact of AM, noting the need for further research to fully understand its sustainability.This paper provides a comprehensive review of the state-of-the-art in metal additive manufacturing (AM), also known as additive manufacturing (AM), direct digital manufacturing, free form fabrication, or 3D printing. AM has the potential to revolutionize global parts manufacturing and logistics by enabling distributed manufacturing and on-demand production, while reducing costs, energy consumption, and carbon footprint. The paper explores the material science, processes, and business considerations associated with achieving these benefits. It highlights the need for a paradigm shift to fully exploit the potential of AM, including advancements in process controls, sensors, and models, as well as metallurgy and mechanical properties. The paper also discusses the challenges in qualification and certification, and the business case for AM, emphasizing its potential to reduce costs and improve efficiency in small production lots. Finally, it addresses the environmental impact of AM, noting the need for further research to fully understand its sustainability.