Background: There are no recent estimates for hypertension-associated medical expenditures. This study aims to estimate hypertension-associated incremental medical expenditures among privately insured US adults. Methods: We conducted a retrospective cohort study using IQVIA's Ambulatory Electronic Medical Records-US dataset linked with PharMetrics Plus claims data. Privately insured adults aged 18-64 years with 1 blood pressure measurement in 2020-2021 were included. Hypertension was identified as having 1 diagnosis code or 2 blood pressure measurements of 140/90 mmHg, or 1 antihypertensive medication in 2021. Annual total expenditures were estimated using a generalized linear model (GLM) with gamma distribution and log-link function. Out-of-pocket (OOP) expenditures were estimated using a two-part model that included logistic and GLM regression. Overlap propensity-score weights from logistic regression were used to obtain a balanced sample on hypertension status. Results: Among the 393,018 adults, 156556 (40%) were identified with hypertension. Compared to individuals without hypertension, those with hypertension had $2,926 (95% CI, $2,681-$3,170) higher total expenditures, and $328 (95% CI, $300-$355) higher OOP expenditures. Adults with hypertension had higher total inpatient ($3,272; 95% CI, $1,458-$5,086) and outpatient ($2,189; 95% CI, $2,009-$2,369) expenditures, when compared with those without hypertension. Hypertension-associated incremental total expenditures were higher for women ($3,242; 95% CI, $2,915-$3,569) than for men ($2,521; 95% CI, $2,139-$2,904). Conclusions: Among privately insured US adults, hypertension was associated with higher medical expenditures, including higher inpatient and OOP expenditures. These findings may help assess the economic value of interventions effective in preventing hypertension.