<p>While the influence of human development on international migration has been widely examined, its implications for internal migration at the subnational scale, particularly in cities, remain largely unexplored. This paper investigates whether internal out-migration from cities initially increases and then decreases over the development process. The study adopts a broad definition of development by incorporating key dimensions such as health, education, and wealth. Through comparative empirical analysis we examine city out-migration based on repeated population censuses in 13 countries across the Global South, covering the entire development spectrum. City-level fixed-effects Poisson regression models are used to analyze socio-demographic and migration data for 313 consistently defined functional urban areas. The analysis reveals that when accounting for unobserved heterogeneity, migration responses to human development turn negative and vary markedly by both development dimension and urban hierarchy. In the largest cities, rising wealth first encourages out-migration but later retains people as opportunity costs increase while health improvements initially reduce migration before eventually enabling more people to move. In intermediate cities education first fuels and later reduces out-migration. These findings advance understanding of migration–development dynamics at the subnational level, highlighting the role of city size and urbanization while challenging the notion of a universal relationship between development and migration. It also contributes to the broader discourse on migration decision-making through the lens of human development.</p>