In response to globalization, leaders have called for more global education in K-12 schools. This study utilized a sequential exploratory mixed methods design to validate the construct teaching for global readiness. After exploratory qualitative analysis of 24 expert teacher interviews, an instrument was developed and administered to K-12 U.S. classroom teachers. Based on EFA and CFA, four factors were interpreted as: situated practice, integrated global learning, critical literacy instruction, and transactional experiences. The end product was a measurement model and scale of teacher practices related to global readiness instruction.