This report presents the recommendations of the WHO Expert Committee responsible for updating the WHO Model List of Essential Medicines. The first part contains a progress report on the new procedures for updating the Model List and the development of the WHO Essential Medicines Library. It continues to present a summary of the Committee's considerations and justifications for additions and changes to the Model List, including its recommendations. Annexes to the main report include the revised version of the WHO Model List of Essential Medicines (the 13th) and a list of all items on the Model List sorted according to their 5-level Anatomical Therapeutic Chemical (ATC) classification codes.