Introduction: As part of the Centers for Medicare and Medicaid Innovation Practice Transformation Network, an integrated healthcare system implemented a multimodal, population health-based hypertension clinical pathway program (HCPP) focused on hypertension management.Aim: To determine whether the HCPP was associated with changes in hypertension control or process-of-care measures and whether associations varied for sites serving higher versus lower proportions of historically underserved patients.Setting: An integrated academic health system encompassing 5 clinic networks and 85 primary and specialty care sites.Program Description: The HCPP was implemented at some sites (adopters) but not others (non-adopters) and had four components: (1) stakeholder engagement; (2) clinical staff retraining; (3) electronic health record-based prompts; and (4) performance monitoring and feedback. Program goals were to encourage clinical teams to increase the frequency of follow up visits and adopt standardized approaches to blood pressure (BP) measurements and antihypertensive medication regimen advancement defined as adding or titrating existing medication.Program Evaluation: This quasi-experimental study used 2017–2019 data from 63,497 patients with hypertension and multivariable difference-in-differences analyses to evaluate changes in outcomes at 19 adopter versus 39 non-adopter sites before and after HCPP implementation. Adoption was associated with 3.5 times differentially greater odds of a BP reassessment (OR 3.5, 95% CI 3.3–3.8), 11% differentially greater odds of BP control (BP<140/90 mmHg) (OR 1.11, 95% CI 1.07–1.15), and 12% differentially greater odds of having non-severely elevated BP (systolic BP < 155 mmHg) (OR 1.12, 95% CI 1.05–1.19). HCPP adoption was not associated with differential changes in 90-day follow-up BP measurement. Adoption was associated with 23% differentially greater odds of appropriate medication advancement (OR 1.23, 95% CI 1.04–1.46). A similar pattern was observed when limiting comparisons to sites caring for a higher proportion of historically underserved populations.Discussion: A multimodal population health approach to transforming hypertension care was associated with improved BP outcomes.