AbstractSegmentation of work from nonwork life is widely presented as desirable to maximize recovery from work. Yet it involves effort which may reduce its positive effects. We present a dual‐process model of segmentation based on integrating boundary theory and self‐regulation theory that shows how creating and maintaining boundaries can have both positive and negative effects. Segmentation allows individuals not only to psychological detach from work, thereby reducing work–nonwork conflict, but can also deplete an individual's momentary capacity for state self‐control, increasing work–nonwork conflict. We tested our model with two studies: a weekly diary study with a sample of 436 individuals and a daily diary study with data collected at two time points each day from 162 participants. Using a Bayesian approach, we find some support for our hypothesized dual pathways. In both studies, psychological detachment mediated a negative relationship between segmentation and work–nonwork conflict. In the daily study, self‐control capacity mediated a positive relationship between segmentation and work–nonwork conflict, but this effect was present only when individuals worked onsite and not when working at home. This article contributes towards understanding the mechanisms explaining the relationship between segmentation and work–nonwork conflict and underscores the importance of self‐regulation in this process.