OBJECTIVES: To describe the occurrence of brain metastases (BMet) and cost offsets of delaying or preventing BMets in ALK+ non-small cell lung cancer (NSCLC) patients in the US. METHODS: Patients with ALK+ NSCLC were identified from a stacked database of PharMetrics Plus and MarketScan claims data from Jan 2008 to Mar 2016 and Dec 2015, respectively. Early BMet was defined as a BMet within 6 months after the first lung cancer diagnosis (index date). The occurrence of a BMet after 6 months was defined as a delayed BMet. Patients with an ALK inhibitor, ≥18 years old, with ≥6 months preindex and ≥30 days follow up were included. ALK+ NSCLC patients were categorized into cohorts of no BMet, early BMet, and delayed BMet. Costs were measured for each BMet category over 12 months, and standardized to per patient per month. RESULTS: The study included 207 (48.7%) patients with no BMet and 218 (51.3%) with BMet. Baseline demographics were similar for age (57 and 54), gender (50% male), and Charlson comorbidity index (mean 1.1). The mean time to a BMet was 210 days (median 39). Among patients with BMet, 140 (64.2%) had early BMet, and 78 (35.8%) had delayed BMet. On average, healthcare costs per month in patients with a BMet was $4,390 higher (median $3,844) compared to no BMet. Among patients with a BMet, the cost of delayed BMet was $12,395 lower per month (median $7,692) than early BMet. CONCLUSIONS: BMet is an important indicator of poor prognosis, and is associated with substantial economic burden. The majority of NSCLC patients are diagnosed early with BMet. Delaying the occurrence of BMet in patients may substantially reduce healthcare cost. This study demonstrates an unmet need for therapies that may prevent or delay the occurrence of BMet in ALK+ NSCLC patients.