In the spring of 2019, the ASME published the first edition of the NM.1, NM.2, and NM.3 standards. These standards are for the design of non-metallic pressure piping systems. The focus is thermoplastics (NM.1), glass-fiber reinforced thermoset resins (NM.2), and material data (NM.3). These standards were developed by the Non-Metallic Pressure Piping Standards Committee, reporting to the ASME Board on Pressure Technology. This paper provides an overview and the technical basis of the design sections of the NM.1 Standard. The focus is the basis design requirements for HDPE, PVC, CPVC, PP, and ABS resins. Also discussed are the mandatory and non-mandatory Appendices applicable to the NM.1 design section.