Tacit intellectual capital (IC) gathers non-explicit organizational knowledge stocks that contribute to supporting business intelligence. This chapter addresses the challenges in tacit IC research and proposes a situational roadmap adaptable to various scenarios to facilitate a deeper understanding of tacit IC. Organizational stocks of knowledge are accumulated through knowledge-flow activities over time. Tacit IC gathers tacit components of intellectual, human, relational, structural, and renewal capital. However, tacit stocks of knowledge are difficult to define. We suggest using Grounded Theory to overcome the research challenges of addressing tacit IC. We propose that Grounded Theory offers a broad and flexible methodological toolbox useful for building a better understanding of tacit IC. This chapter contributes to tacit IC theoretical development and provides practical ways of advancing tacit IC research gap-spotting, the tacit IC literature review process, and tacit IC research coding processes and data analysis; all these advances will benefit our understanding of tacit IC. We believe that such research development will reveal and clarify practical implications. We conclude by offering future IC research tips and presenting forthcoming tacit IC practices that will support a sustainable competitive advantage.