As health care attempts to bridge the gap between evidence and practice, the concept of the learning health system (LHS) is becoming increasingly relevant. LHS integrates evidence with health systems data, driving health care quality and outcomes through updates in policy, practice, and care delivery. In addition, LHS research is becoming critically important as there are several initiatives underway to increase research capacity, expertise, and implementation, including attempts to stimulate increasing numbers of LHS researchers. Physical Medicine & Rehabilitation (PM&R) physicians (physiatrists), nurses, therapists (physical therapists, occupational therapists, speech therapists, clinical psychologists), and scientists are affiliated with LHSs. As LHS research expands in health care systems, better awareness and understanding of LHSs and LHS research competencies are key for rehabilitation professionals including physiatrists. To address this need, the Agency of Healthcare Research and Quality (AHRQ) identified 33 core competencies, grouped into eight domains, for training LHS researchers. The domains are: (1) Systems Science; (2) Research Questions and Standards of Scientific Evidence; (3) Research Methods; (4) Informatics; (5) Ethics of Research and Implementation in Health Systems; (6) Improvement and Implementation Science; (7) Engagement, Leadership, and Research Management; and the recently added (8) Health and Healthcare Equity and Justice. The purpose of this commentary is to define LHS and its relevance to physiatrists, present the role of implementation science (IS) in LHSs and application of IS principles to design LHSs, illustrate current LHS research in rehabilitation, and discuss potential solutions to improve awareness and to stimulate interest in LHS research and IS among physiatrists in LHSs.