Objective: To estimate national prevalence and direct incremental expenditures in Chronic Obstructive Pulmonary Disease (COPD) and asthma using 2007 Medical Expenditure Panel Survey (MEPS) data. <br>Methods: COPD and asthma were identified using ICD-9 codes and were the main independent variables. Covariates included age, gender, race, income, region, insurance and marital status. Dependent variables were total health care, office-based, outpatient, inpatient, emergency room and prescription expenditures. Descriptive statistics and regression analysis were used to fulfill the study objectives. <br>Results: Prevalence of COPD and asthma was 1.3 million and 28.3 million, respectively. Total direct incremental health care expenditures per person for COPD and asthma were $1,739.27 and $2,133.83, respectively. High cost categories among COPD and asthma included office-based, inpatient and prescription expenditures. Age, gender, region, insurance and marital status were significant predictors for health care expenditures. <br>Conclusion: Results highlight socio-demographic disparities and high health care expenditures due to COPD and asthma in the United States. <br>Keywords: Asthma, COPD, Medical Expenditures Panel Survey (MEPS), incremental health care expenditures, retrospective analysis / Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences / Pharmacy Administration / MS / Thesis