According to the literature, development of expertise is directly correlated with three fundamental requirements: a) a tremendous amount of dedicated work, b) time, and c) relevant experience. Experts in most domains attain their highest level of performance after 10,000 hours of dedicated practice. This is equivalent to ten years of dedicated and relevant experience within the expert’s respective domain. Within the domain of critical care nursing the skill level of the bedside nurse has been directly correlated with quality patient outcomes, greater reimbursements, and decreased operational costs. The purpose of this grounded theory study was to explore the emic perspective of the critical care nurse as it relates to expertise, expert performance and the critical care nurses journey in the achievement of expert performance. Benner’s model of skill acquisition, Novice to Expert, provided the theoretical structure and framework. However, as expertise was considered within the dynamic critical care environment, Ericsson and Smith’s expert performance approach was used to strengthen Benner’s Novice to Expert Model providing valuable structure and insight into the concept of expertise. As themes were identified the expert performance approach provided valuable evaluative strategies to facilitate understanding of expert nuances and processes within critical care practice. Study findings supported three major themes: a) experience with sub-themes diversity and intensity; b) knowledge with the sub-theme critical reasoning; and c) self-actualization with sub-themes personal presence, and life-long learning. Furthermore, data findings supported the researcher’s assertion that “tacit” knowledge is a more appropriate term to represent the requisite knowledge base and diversity of experience demonstrated by nurses in actual clinical practice rather than the term “intuitive grasp” as found in current literature. Research findings of this study will help educators and nursing leadership better understand the transition from novice to expert critical care nurse within the context of clinical nursing practice. In so doing, nursing leadership will have the tools and the added insight to facilitate that transition in the most efficient manner possible thereby improving not only professional satisfaction but patient outcomes and cost as well.