This chapter discusses intercultural adaptation in the context of globalization and migration. It introduces a multi-level framework to analyze adaptation at the micro, meso, and macro levels. At the macro level, theories include push-pull, world systems theory, melting pot, and pluralism. Micro theories examine migrant-host relationships through assimilation, separation, integration, and intercultural transformation. Meso theories analyze migrant networks and social capital. The chapter also explores the challenges of modern migration and the four types of migrant groups.