The recent publication of the Physical Therapy Evaluation and Treatment After Concussion Clinical Practice Guideline is intended to assist clinicians in their decision-making specific to evaluation and intervention. Clinical practice guidelines are supported by best available evidence, though it is unknown what other factors drive clinical decision-making in the realm of concussion management. The purpose of this study was to explore factors related to the process of clinical decision-making of experienced physical therapists who treat individuals with concussion. This grounded theory approach used semi-structured interviews of physical therapists who have practiced concussion management ≥3years and have treated ≥15 individuals for postconcussion symptoms in the last year. Following the inductive approach, deductive qualitative methodology was used to explore alignment with recent guidelines. Member checking was used to ensure trustworthiness. Ten therapists' experience in treating concussion ranged from 5 to 20years. Four overarching themes were identified that contribute to clinical decision-making: expert practice behaviors through use of reflection in action, clinical reasoning, collaboration, and evidenced informed practice; therapeutic alliance building using individualized education, reassurance, and relationship building; adaptability in prioritizing, assessing, and responding to patients' needs; and listening and observing. Clinician decision-making statements showed alignment with clinical practice guideline recommendations. Experienced therapists demonstrate a consistent approach that parallels the current clinical practice guideline while building off clinical experience to tailor individualized care focusing on patient centeredness. These factors may assist more novice clinicians to develop and improve their management strategies for optimal outcomes. Identified themes may broaden frameworks and guidelines for the management of individuals postconcussion specific to the field of physical therapy.