Open online courses focused on teacher professional development (PD) have been challenged by many of the same disengagement problems documented in the general Massive Open Online Course (MOOC) literature. A promising solution is the introduction of course designs with additional flexibility for time management that allow participants to more effectively self-regulate their learning. The present research aims to (a) describe high-level engagement in a new course design that provides additional time for participants to complete their learning objectives and (b) examine the relationship between engagement during the extended period, completion of course certificate requirements, and reported changes in professional practice. Results suggest participants utilize the extension period, and activity during that time is related to completion and change in practice.