I understand that connections, research record will play a major role in landing an interview for a national lab job, even for a staff scientist position, and I wouldn't be opposed to working in a national lab after graduation (and any appropriate postdocs). However, that is not my question. As I am not an US citizen, I feel that I would be at a disadvantage in an attempt to land such a permanent job. Perhaps my advisor is wrong on that count but since national labs are under the purview of the DOE, permanent jobs (as defined by USCIS) at national labs are primarily offered to US citizens, or US citizenship could even be a requirement. But do permanent jobs at national labs actually have any requirements pertaining to citizenship? Or can a national lab sponsor an EB-2 green card if the position is permanent (or H-1B if the position is temporary)?