Additive manufacturing is a disruptive technique to release design freedom in alloy components. However, materials and processing design for additive manufacturing also introduces new challenges due to different process-structure-property relationships. In this talk, we will perform an ICME (integrated computational materials engineering) gap analysis based on studies of alloys prepared by different additive manufacturing techniques, including powder bed fusion, powder-based directed energy deposition, and wire-arc additive manufacturing. The differences in the structure-property correlations due to various manufacturing processes will be discussed. Post-processing and their sequence on mechanical performance, such as fatigue resistance, will be emphasized. Furthermore, we will explore opportunities in microstructure engineering of steel and superalloys for additive manufacturing and its post-processing. Conventional casting alloy studies are used to benchmark such an ICME gap analysis. The research performed in the same alloy system using different manufacturing techniques calls for the ad-hoc post-processing design as well as uncertainty quantification.