Scientific communities expect early career researchers to become intellectually independent and to develop longer-term research plans. How such programs emerge during the early career phase is still poorly understood. Drawing on semistructured interviews with German ECRs in plant biology, experimental physics, and early modern history, we show that the development of such a plan is a research process in itself. The processes leading to IRPs are conditioned by the fields’ epistemic practices for producing new knowledge. By linking the conditions under (...) which ECRs work to the epistemic properties of their IRPs, we identify mechanisms that produce these programs and conditions facilitating or hindering the operation of these mechanisms. (shrink)