This study contributes to the growing body of research on the role of crosscutting concepts (CCCs) in three-dimensional teaching and learning by examining the complexity of elementary preservice teachers' (PSTs) knowledge for teaching related to CCCs. The researchers used qualitative methods to analyze PSTs' responses to a questionnaire about CCCs in three-dimensional learning and think-aloud interviews with nine PSTs about this questionnaire. The PSTs' responses suggest patterns and variations in their selection and justification of CCCs in relation to different scientific phenomena. These analyses highlight how different individuals likely see different CCCs as having "exploratory power" for the related phenomena and DCIs. The findings suggest that the knowledge required for effective teaching of CCCs as part of three-dimensional learning is complex and multifaceted. The study provides valuable insights into the strengths and limitations of elementary PSTs' understanding of CCCs and has the implications for supporting three-dimensional learning and teaching.