In 2013, CDC published a comprehensive analysis outlining the top 18 antibiotic-resistant threats in the U.S., titled Antibiotic Resistance Threats in the United States, 2013 (AR Threats Report). The report ranked the 18 threats (bacteria and fungi) into three categories based on level of concern to human health—urgent, serious, and concerning. CDC is working towards releasing an updated AR Threats Report in fall 2019.