This article draws upon concepts developed in recent empirical and theoretical work on high skilled and academic mobility and migration including accidental mobility, forced mobility and negotiated mobility. These concepts inform a situated, qualitative study of mobility among international postdoctoral researchers in life sciences and engineering fields who were employed at US and UK universities in 2008 and 2009. Informed by epistemological methods in the Foucauldian tradition of discourse and governmentality, the study explores how policy discourse and technologies empower and limit scientists and engineers in negotiating employment arrangements across national boundaries.