ANSI/ASHRAE/IES Standard 90.1 is the U.S. national commercial building model energy code and it has a significant impact on many programs and policies that impact energy savings across the United States and the world. Determining the energy savings from the latest edition of Standard 90.1 relative to previous editions is critical for beyond code programs and for others setting energy performance targets. Pacific Northwest National Laboratory developed prototype building models to determine the energy savings from 90.1-2016 standard. This paper presents the rigorous modeling and development process that PNNL has established and its applications. In addition, the energy savings results ofStandard 90.1-2016 are described.