This paper investigates the economic assimilation of rural-urban migrants in Indonesia. I use cross-sectional, synthetic cohort, and panel data techniques. The estimates suggest that migrants do not experience earnings penalties subsequent to their arrival in urban areas. Instead, they have persistently higher earnings relative to urban natives. However, this is accompanied by a worsening mental health status due to a lack of social support. The findings on the earnings premium are in contrast to earlier studies in countries with more restrictive policies for rural-urban migration, such as China and Vietnam.