This topic brief is one in a series on personalized learning prepared for Conversations with Innovators, 2018. Personalization refers to a teacher's relationships with students and their families and the use of multiple instructional modes to scaffold each student's learning and enhance the student's personal competencies. Personalized learning varies the time, place, and pace of learning for each student, enlists the student in the creation of learning pathways, and utilizes technology to manage and document the learning process and access rich sources of information. On the Center on Innovation in Learning (CIL)'s graphic model of personalized learning, instructional design forms the foundation of a house, and the floors, walls, and roof depict other elements of the CIL's conceptual model. Why is "instructional design" pictured as the foundation of personalization? For this simple reason: Learning cannot be personalized without being explicitly planned by the teacher and thoughtfully integrated into the teacher's instructional scheme. This report discusses how instructional design relates to personalized learning.