This Funding Opportunity Announcement (FOA) will support pilot, feasibility or exploratory research in 5 priority areas in substance use epidemiology and health services, including: 1) responses to sudden and severe emerging drug issues (e.g. the ability to look into a large and sudden spike in opioid or synthetic cannabinoid use/overdoses in a particular community); 2) responses to emerging marijuana trends and topics related to the shifting policy landscape; 3) responses to unexpected and time-sensitive prescription drug abuse research opportunities (e.g., new state or local efforts); 4) responses to unexpected and time-sensitive medical system issues (e.g. opportunities to understand addiction services in the evolving health care system); and 5) responses to unexpected and time-sensitive criminal or juvenile justice opportunities (e.g. new system and/or structural level changes) that relate to drug abuse and access and provision of health care service. It should be clear that the knowledge gained from the proposed study is time-sensitive and that an expedited rapid review and funding are required in order for the scientific question to be answered (i.e. an imminent policy change will not allow for standard review and funding timeline).