The National EMS Information System (NEMSIS) launched an update to the National EMS Data Standard that will be widely implemented this year and next. NEMSIS Version 3.5 has far-reaching implications to data quality, collection, and utilization. We will review the purpose and value of a national standard, introduce changes to the information collected in the field with implementation of v3.5, and discuss how clinicians, agencies, states, and national partners are using EMS data to improve EMS response.