BACKGROUND: Asthma, a chronic respiratory disease, is associated with high economic burden. This study estimates per-worker medical and incremental medical costs associated with treated asthma by socioeconomic and demographic characteristics, industries, medical events, and sources of payments for workers aged ≥18 years. METHODS: We analyzed Medical Expenditure Panel Survey data from 2018 to 2020 to assess medical costs for treated asthma among workers using the International Classification of Diseases, Tenth Revision, Clinical Modification code for asthma (J45). We used two-part regression models to estimate medical and incremental medical costs controlling for covariates. All results are adjusted for inflation and presented in 2022 US dollar values. RESULTS: An estimated annual average of 8.2 million workers out of 176 million had at least one medical event associated with treated asthma. The annualized estimated per-worker incremental medical costs for those with treated asthma was $457 and was highest among: those in the age group of 35-44 years ($534), in the western region ($768), of Hispanic ethnicity ($693), employed in the utility and transportation industries ($898), males ($650), and for inpatient admissions ($754). The total annualized medical costs of treated asthma was $21 billion and total of incremental medical costs was $3.8 billion. CONCLUSION: Findings of higher incremental medical costs for treated asthma among workers in certain socioeconomic, demographic, and industry groups highlight the economic benefit of prevention and early intervention to reduce morbidity of asthma in working adults. Our results suggest that the per-person incremental medical costs of treated asthma among workers are lower than that for all US adults.