BACKGROUND Although pulmonary congestion can be quantified in heart failure (HF) by means of lung ultrasonography (LUS), little is known about LUS findings (B-lines) in different HF phenotypes. This prospective cohort study investigated the prevalence and clinical and echocardiographic correlates of B-lines in ambulatory HF patients with preserved (HFpEF) or reduced (HFrEF) ejection fraction compared with hypertensive patients. We related LUS findings to 12-month HF hospitalizations and all-cause mortality. RESULTS We used LUS to examine hypertensive (n = 111), HFpEF (n = 46), and HFrEF (n = 73) patients (median age 66 y, 56% male, 79% white, and median EF 55%) undergoing clinically indicated outpatient echocardiography. B-line number was quantified offline, across 8 chest zones, blinded to clinical and echocardiographic characteristics. The proportion of patients with ≥3 B-lines was lower in hypertensive patients (13.5%) compared with both HFrEF (45.2%, P < .001) and HFpEF (34.8%; P = .05). HF patients with ≥3 B-lines had a higher risk of the composite outcome (age- and sex-adjusted hazard ratio 2.62, 95% confidence interval 1.15-5.96; P = .022). CONCLUSIONS When performed at the time of outpatient echocardiography, LUS findings of pulmonary congestion differ between patients with known HF and those with hypertension, and may be associated with adverse outcomes.