We offered professional development to in-service K-12 teachers. Teachers learned programming, and how to teach programming. During the subsequent academic year, they taught programming in their schools. We interviewed the teachers to better understand their experiences. This poster describes case studies of K-12 teachers as they teach programming for the first time. As this study is qualitative, it does not attempt to measure findings. Rather, in exploring individual teachers' experiences, we hope to benefit both future teachers who will need to teach computing as well as those who will be helping those teachers.