The author examines social mobility in the enlarged EU by analysing the work sequences of 1865 movers and stayers in Poland. Using indicators of upward and downward social mobility, she explores the role of migration in careers. Her research shows that migration adds dynamism to work paths and contributes to the improvement of people¿s working lives. It also suggests that agency and reflexivity guide the acquisition of tacit skills during migration, resulting in various patterns of social mobility.