While the literature on business-IT alignment has become increasingly mature in the past 20 years, different definitions and conceptualizations have emerged. Several dimensions like strategic, intellectual, structural, social, and cultural alignment have been developed. However, no integrated and broadly accepted categorization exists and these dimensions are non-selective and do overlap. In this paper, we critically compare and reflect the existing dimensions of alignment and synthesize what has been researched about alignment and guide future research by revealing gaps in alignment research suggesting an agenda for future research. In regard to analyzing alignment, we propose to clearly separate between the organizational level and the content of alignment, for which we suggest three distinct dimensions: (1) human dimension; (2) social dimension; (3) intellectual dimension. The result is a consolidated grid of alignment studies allowing to identify both areas with a mature and rich strand of literature and those lacking research.