Abstract: A leading organizer of the global advocacy movement to reform immigration detention regimes explores efforts by civil society organizations to engage governments. Through an examination of the tensions at play between human rights standards, political and public opinion, and the pragmatics of operationalizing entry and exit systems, this chapter highlights advocacy strategies that have proved effective in promoting non-detention models. Focusing on “alternatives to immigration detention” in a range of political and migration contexts, the article draws from comparative case studies and the experiences, challenges, and successes of the International Detention Coalition (IDC) and its members.