Objective: To provide updated prevalence estimates of asthma and asthma medication use for women of childbearing age in the United States.Methods: Using data from 11,383 women aged 18-44, including a subset of 1,245 pregnant women, enrolled in the National Health and Nutrition Examination Survey (2001-2016), we assessed the age-adjusted prevalence of self-reported diagnosed asthma. For women aged 18-44, we stratified by year, demographics, and other characteristics. Furthermore, we assessed asthma medication use among women aged 18-44 with asthma.Results: After age-adjustment, 9.9% (95% confidence interval (CI) 9.2%, 10.7%) of women aged 18-44 and 10.9% (95% CI 7.2%, 14.6%) of pregnant women reported having asthma. Asthma prevalence was highest in 2015-2016 (12.0% 95% CI 9.8%, 14.3%) and lowest in 2003-2004 (8.6% 95% CI 6.4%, 10.8%). Women aged 18-44 with Medicaid or State Children's Health Insurance Program insurance coverage (16.8% 95% CI 14.5%, 19.2%), obesity (14.4% 95% CI 12.9%, 15.8%), diabetes (18.7% 95% CI 12.1%, 25.2%), hypertension (16.6% 95% CI 14.2%, 19.0%), and current smokers (12.8% 95% CI 11.4%, 14.2%) had the highest asthma prevalence. Of women with asthma, 38.3% (95% CI 34.5%, 42.1%) reported using asthma medications in the past 30 days.Conclusions: Among women of childbearing ages, asthma burden varies across demographic and clinical characteristics and has increased in recent years.