This study investigated initial implementation processes of the Common Core State Standards (CCSS) in public and private schools in a single Louisiana district. Results suggested participants' high level of concern in many aspects of the implementation of the CCSS in public schools related to timeline and instability of curriculum decisions, which negatively affected teachers' confidence levels. Private school teachers experienced greater stability in their curricula, a more feasible timeline of implementation, positive professional development, and positive experiences with CCSS implementation, affecting their teacher identity and impact on students. However, public school teachers reported instability in their curricula, difficult timelines of implementation, unsupportive professional development, and overall negative experiences, affecting their teacher identity and impact on students with the implementation of the CCSS.