A strength of substantive grounded theories is that they are modifiable. Yet, little attention is given in the research literature to the evolution of grounded theories through the process of emergent fit. In this article, emergent fit is discussed, and the evolution of the theoretical understanding of relationships with helping systems is provided as an example. In a feminist grounded-theory study of women's caring, emergent fit with existing inductive research on health care relationships resulted in a framework of negotiating, which includes four strategies: reframing responsibility, becoming an expert, harnessing resources, and taking on more. This explanatory model demonstrates how the use of emergent fit can avoid the generation of isolated theories and contribute to knowledge accumulation by producing a substantive theory with wider applicability.