Public management reforms have promoted a new type of public career: boundaryless employees following lateral career trajectories in different organizations. The literature opposes boundaryless careers to the traditional career for life, based on vertical trajectories of promotion and tenure. The implicit image of the boundaryless careerist is one of fast-moving, intrinsically motivated professionals who self-direct their career across "old" organizational barriers. In this article, we study whether boundaryless career mind-sets are the vanguard of a more flexible and mobile workforce. We describe how many public employees experience boundaryless career mind-sets, and we analyze what drives them. Our research shows that boundaryless mind-sets are still rather exceptional. The traditional career mind-set within the organization prevails and many employees are very satisfied with it. Only public employees who are highly educated, invest in their own career and networks, and were successful in previous mobility experiences report a boundaryless career mind-set. Nevertheless, our research also points to a higher potential for boundaryless career mind-sets.