The literature on professional socialization suggests that their training and socialization lead physicians to prioritize professionally prescribed activities over entrepreneurial activity. This leaves unexplained how and why early career physicians would engage in entrepreneurship, a behavior that many healthcare organizations now seek to encourage. To address this shortcoming, we conducted an inductive study, augmented with survey data, of UK National Health Service physicians involved in entrepreneurial projects. We detail a process of physician entrepreneurship underpinned by organizational improvement motives and identification with the organization. Entrepreneurs breached constraining roles and formed ventures which originated as intrapreneurial initiatives but shifted to individual-level resourcing. Entrepreneurial behaviors coincided with physicians’ commitment to remain with the NHS albeit with adjustments to their career plans. Overall, the study suggests that physicians manage the pressure exerted by professional socialization by adapting both the kind of entrepreneurial projects and career pathways they pursue.