This guide provides national stakeholders and advocates with information and guidance to update the national essential medicines list to include a new commodity, a new indication, or a new formulation based on the available evidence and based on country need and disease burden. While the actors, timeline, and process may vary from country to country, this guide presents the broad steps involved in revising an EML for any health commodity. Additional resources and a glossary are included to provide supplemental information and to clarify key terms.