This manual is intended primarily for victim service agency staff and other social service providers, who will administer the Trafficking Victim Identification Tool (TVIT) to clients who are potential trafficking victims. Law enforcement, health care and shelter workers will also find it helpful in improving trafficking victim identification, especially in conjunction with appropriate training or mentoring. The manual content is based on results of research conducted by the Vera Institute of Justice, which collaborated with leading legal and victim services agencies in the United States, to produce the validated screening tool and best practices for identifying trafficked persons, and on other expert sources in government and non-governmental agencies. Vera’s research found that the TVIT instrument is highly reliable in predicting both labor and sex trafficking in women and men and among foreign- and U.S. born victims. The screening tool can be used in its short version (consisting of 16 core questions, plus questions specific to migration for the foreign-born) without loss of predictive ability, or in its longer form, depending upon the situation and purpose of screening. As with any kind of information gathering from victims of crime, it is essential that screening for trafficking be done with care.