Niamh McQuillan, development and instructional coach at Windsor Mill Middle School in Baltimore County Public Schools, Maryland, writes here that, as a teacher, she always liked new learning, but more often than not, it was like a barnacle on her practice. She attended professional development sessions and took the handout back to the to-do tray in her classroom with the full intention of incorporating it into a lesson that week. Without fail, something would come up and that wouldn't happen. Tasked with bringing relevant professional development to the middle school where she works now, McQuillan describes in this article how she and the professional development team at her school implemented a structure for teacher learning with Inside-Out Professional Development (PD) centered around four inquiry teams--areas identified as crucial learning for their school: (1) Standards-based planning and effective feedback; (2) Higher-order thinking; (3) Targeted small-group instruction; and (4) Project-based learning. The group had two central ideas: (1) professional development would be generated from inside the teachers' classrooms; and (2) the demands placed on teachers would be streamlined. For additional support, teachers had a go-to partner. From the onset, the principal wanted to ensure that all teams had access to one another's learning. The group planned a virtual professional development via TodaysMeet in October, a schoolwide learning walk in January, and an end of-the-year real-time share in May.