Each year, CALSTART and the California Air Resources Board (CARB) conduct technology status and market readiness snapshot assessments to analyze the technology and market progress of zero-emission medium- and heavy-duty (ZE MHD) vehicle and equipment technologies. This report explains the methods and process used to create and update these assessments, which depict a comprehensive view of ZE MHD vehicle and equipment platform performance and readiness for the marketplace. This report will be updated on a periodic basis in support of the publication of CARB’s Appendix D: Long-Term Heavy-Duty Investment Strategy. A previous version of this report was published in October 2022.