OBJECTIVES: To evaluate whether hospitalization rates differ between COPD patients who switched therapy and/or have better medical management in the Medicare population. METHODS: This is a cross-sectional retrospective study of COPD Medicare patients between January 2006 and December 2008. Eligible patients had at least one claim for COPD in 2006 as 1st diagnosis and were also continuously eligible for parts A, B and D during the study period. Patients enrolled in Medicare Advantage, diagnosed with asthma and younger than 65 years old were excluded. Therapy switch was defined as patient switching all drugs taken in the previous year. Probability of hospitalization was estimated using a logit model with regressors of age, gender, race, previous hospitalization, previous therapy, previous COPD test, physician visits and comorbidities. RESULTS: A total of 44,933 patients were included in the study. The average age was 77.8 years old. A majority of the patients were female (64.1%), and white (89.8%). Congestive heart failure, diabetes and hyperlipidemia were the most common comorbidities. The most frequently prescribed therapy was oxygen (around 30%), followed by Short-Acting Beta Agonists (14%). Patients who received greater COPD medical management as defined as COPD therapy (including higher OCS use), number spirometry tests and physician visits for COPD were associated with decreased likelihood of hospitalization in 2008 (p-value<0.05). Moreover,  therapy discontinuation, new therapy starters, weight loss, hyperlipidemia, liver disease, coagulapathy and renal failure were associated with higher COPD hospitalization risk while depression, congestive heart failure with lower hospitalization risk (p-values <0.05). Also, in this population around 21% visited a specialist physician, 14% had ER visit and 20% were hospitalized for COPD in 06, 07, 08. CONCLUSIONS: The findings suggest that patients maintaining the same therapy across years and patients with greater COPD medical management are less likely to be hospitalized compared to patients with worse disease control.