We examine the well-being effects of a regularization program offered to half a million Venezuelan forced migrants in Colombia. We collected data on more than 2000 such migrants and compared the well-being of those who arrived in Colombia before and after the date that defined program eligibility. Since this date was announced ex-post and was unknown to the public, we could credibly evaluate the program’s impact. We find that program beneficiaries experienced large improvements in well-being, including consumption per capita (a gain of 48%), monthly labor income (an increase of 22%), and health status (an increment of 1.2 standard deviations). These positive outcomes largely stemmed from improved access to services, particularly the social protection system, subsidized healthcare system, and financial services. We also find that the fiscal costs incurred by the Colombian government for a regularized migrant household are lower than those for an irregular migrant household.