OBJECTIVE: To characterize trends in the acute management (within 30 days) after lateral ankle sprain (LAS) in the United States. DESIGN: Descriptive epidemiology study. PATIENTS: Of note, 825 718 ankle sprain patients were identified; 96.2% were patients with LAS. Seven percent had an associated fracture and were excluded from the remaining analysis. SETTING: Primary and tertiary care settings. INTERVENTIONS: We queried a database of national health insurance records for 2007 to 2011 by ICD-9 codes for patients with LAS while excluding medial and syndesmotic sprains and any LAS with an associated foot or ankle fracture. MAIN OUTCOME MEASURES: The percentage of patients to receive specific diagnostic imaging, orthopedic devices, or physical therapy treatments within 30 days of the LAS diagnosis and the associated costs. RESULTS: Over two-thirds of patients with LAS without an associated fracture received radiographs, 9% received an ankle brace, 8.1% received a walking boot, 6.5% were splinted, and 4.8% were prescribed crutches. Only 6.8% received physical therapy within 30 days of their LAS diagnosis, 94.1% of which performed therapeutic exercise, 52.3% received manual therapy, and 50.2% received modalities. The annual cost associated with physician visits, diagnostic imaging, orthopedic devices, and physical therapy was 152 million USD, 81.5% was from physician evaluations, 7.9% from physical therapy, 7.2% from diagnostic imaging, and 3.4% from orthopedic devices. CONCLUSIONS: Most patients with LAS do not receive supervised rehabilitation. The small proportion of patients with LAS to receive physical therapy get rehabilitation prescribed in accordance with clinical practice guidelines. The majority (>80%) of the LAS financial burden is associated with physician evaluations.