OBJECTIVES:  The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines recommends maintenance inhaler use based on disease severity but offers limited guidance for acute inhaler use. The study aims to examine the relationship between chronic obstructive pulmonary disease (COPD) severity and acute inhaler use, alone or in conjunction with maintenance medications.  METHODS: Using 5% sample of Medicare administrative claims from Chronic Condition Data Warehouse from 2006-2011, beneficiaries diagnosed with COPD were followed for two years. Individuals with at least 1 COPD-related inpatient visit, COPD-related emergency department visit, or supplemental oxygen claim during first six months of follow-up were categorized with moderate-severe COPD; otherwise, subjects were classified with mild COPD. Severity cohorts were compared on acute and maintenance inhaler use. Acute inhaler use per year was categorized into six groups (>0 to ≤2, >2 to ≤4, >4 to ≤6, >6 to ≤8, >8 to ≤10, and >10 to ≤12). RESULTS: