NMASSIST is a screening tool for drug use in general medical settings. Also called NIDA Quick Screen, it is a web-based interactive tool that guides clinicians through a short series of screening questions and, based on the patient's responses, generates a substance involvement score that suggests the level of intervention needed. The tool also provides links to resources for conducting a brief intervention and treatment referral, if warranted. This screening instrument, a modified version of the World Health Organization's Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), is appropriate for patients age 18 or older. It can be completed by either a clinician or the patient using an online form or a printed version of the instrument, and is easily scored. It provides information about the substances people have ever used in their lifetime, the substances used in the last three months, problems related to substance use, risk of current or future harm, dependence, and injecting drug use.