This handbook presents the determinants of migrant vulnerability (DOMV) model for analyzing and responding to migrant vulnerability. The DOMV model is specifically designed to address the protection and assistance needs of a specific subset of migrants: those who have experienced or are vulnerable to violence, exploitation, and abuse before, during or after the migration process.The handbook further presents best practices and lessons learned in migrant protection and assistance, based on IOM’s extensive experience in providing protection and assistance services to trafficked and other vulnerable migrants, and on the provision of return and reintegration services to migrants from around the globe.