Achalasia is a debilitating chronic condition of the esophagus. Currently there are no national estimates on the epidemiologic and economic burden of disease. We sought to estimate trends in incidence and prevalence of achalasia by age-sex strata, and to estimate the total direct medical costs attributed to achalasia in the United States. We conducted a cohort study using two administrative claims databases: IBM MarketScan Commercial Claims and Encounters database (2001-2018; age <65) and a 20% sample of nationwide Medicare enrollment and claims (2007-2015; age ≥65). Point prevalence was calculated on the first day of each calendar year; the incidence rate captured new cases developed in the ensuing year. Utilization rates of healthcare services and procedures were reported. Mean costs per patient were calculated and standardized to the corresponding U.S. Census Bureau population data to derive achalasia-specific total direct medical costs. The crude prevalence of achalasia per 100,000 persons was 18.0 (95% CI, 17.4, 18.7) in MarketScan and 162.1 (95% CI, 157.6, 166.6) in Medicare. The crude incidence rate per 100,000 person-years was 10.5 (95% CI, 9.9, 11.1) in MarketScan and 26.0 (95% CI, 24.9, 27.2) in Medicare. Incidence and prevalence increased substantially over time in the Medicare cohort, and increased with more advanced age in both cohorts. Utilization of achalasia-specific healthcare was high; national estimates of total direct medical costs exceeded $408 million in 2018. Achalasia has a higher epidemiologic and economic burden in the US than previously suggested, with diagnosis particularly increasing in older patients.