Throughout elementary education, foundational literacy has been one of the essential components of students' reading and writing abilities. For students to be successful in their literacy skills, it is necessary for them to be afforded systematic word study instruction through the intentional teaching of foundational skills along with multisensory strategies. The purpose of this mixed-method action research study was to broaden the base of understanding of professional development in multisensory word study instruction in the context of balanced literacy classrooms, and its impact on effective planning of experienced second-grade teachers to improve student achievement. Additionally, word study instruction was emphasized through professional development at the classroom level as a preventive service for students. As a result, a shift in instructional practices created a significant awareness in teacher and principal practices of professional development delivery. This provided an understanding that word study was effective, despite some challenges of learners in their stages of early literacy development. Lastly, when teachers strive to improve their craft, there is greater agency over their own educational practices for promoting student learning. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]