Characterizing students' knowledge and skill upon kindergarten entry has implications for early learning and K-12 outcomes and systems alignment. Large-scale entry assessments measure skillsets shown important for later success, so that meaningful comparisons and appropriate decisions can be made. Consequently, it is important to document the factor structure and measurement invariance of such assessments so that test-based performance, and thus, students' actual knowledge and skills are accurately represented. Whereas invariant structures provide evidence that the same skillsets are measured across groups, variant structures imply systematic bias, which can threaten the ability to meaningfully compare students and draw valid inferences. This study examines the underlying dimensions of a statewide kindergarten entry assessment and its measurement invariance across several key demographic groups.