OBJECTIVES According to data from the National Health Interview Survey, an estimated 22 million Americans had asthma in 2005. Previous estimates of the cost of asthma are outdated; therefore, there is not a clear understanding of the value of resources that are used for asthma care and the loss of productivity to society. This study seeks to estimate the cost of asthma to society in 2006 through evaluating direct medical expenditures and indirect costs. METHODS The expenditure attributable to asthma for health care events (office based visits, emergency department visits, inpatient stays, outpatient visits, and prescription medications) is estimated using the two-step regression technique on 2006 data from the nationally representative Medical Expenditure Panel Survey (MEPS). Work and school absentee days attributable to asthma are estimated using negative binomial regression and are valued following the human capital approach. The authors rely on published estimates for the value of the loss of life from premature death. RESULTS Using data from 2006, having asthma resulted in an estimated additional $1308 (in 2006 dollars) in direct medical expenditures per person with asthma, of which almost half ($734) is attributable to prescription medication. Asthma was responsible for an excess of approximately 2.6 school days missed per student with asthma and an excess of approximately 1.7 working days lost per person in the labor force with asthma, costing society an estimated US$2.3 billion. CONCLUSIONS This paper updates past estimates of the total cost of asthma to society through employing recent data and methods. These estimates may be used to articulate both the monetary burden of asthma and the savings that are achievable when programs aimed at managing asthma are successful at reducing preventable health care utilization.