The extent to which teachers' level of efficacy and quality of instructional performance changed after they received a professional development workshop on instructional alignment was unknown, Therefore, this researcher focused this inquiry on teachers in a Florida school district, investigating how professional development on standards and assessment alignment would impact teachers' self-efficacy level in writing lesson plans. Results indicated that teachers' level of efficacy and quality of instructional performance, measured as their beliefs on how alignment can benefit their students and improve how they write lesson plans, showed overall improvement after undergoing professional development. These findings can be used to initiate positive social change, starting with the field of education. The results benefit both teachers and students, as well as administrators and school districts. State and federal policymakers can also benefit from this evidence regarding the positive impact of professional development on improving instructional alignment.