In patients with type 2 diabetes mellitus, sodium-glucose cotransporter 2 inhibitors reduce the risk of hospitalization for heart failure (HHF). We assessed the effect of ertugliflozin on HHF and related outcomes. VERTIS CV (Evaluation of Ertugliflozin Efficacy and Safety Cardiovascular Outcomes Trial), a double-blind, placebo-controlled trial, randomly assigned patients with type 2 diabetes mellitus and atherosclerotic cardiovascular (CV) disease to once-daily ertugliflozin 5 mg, 15 mg, or placebo. Prespecified secondary analyses compared ertugliflozin (pooled doses) versus placebo on time to first event of HHF and composite of HHF/CV death, overall and stratified by prespecified characteristics. Cox proportional hazards modeling was used with the Fine and Gray method to account for competing mortality risk, and Andersen-Gill modeling to analyze total (first+recurrent) HHF and total HHF/CV death events. A total of 8246 patients were randomly assigned to ertugliflozin (n=5499) or placebo (n=2747); n=1958 (23.7%) had a history of heart failure (HF) and n=5006 (60.7%) had pretrial ejection fraction (EF) available, including n=959 with EF ≤45%. Ertugliflozin did not significantly reduce first HHF/CV death (hazard ratio [HR], 0.88 [95% CI, 0.75-1.03]). Overall, ertugliflozin reduced risk for first HHF (HR, 0.70 [95% CI, 0.54-0.90]; P=0.006). Previous HF did not modify this effect (HF: HR, 0.63 [95% CI, 0.44-0.90]; no HF: HR, 0.79 [95% CI, 0.54-1.15]; P interaction=0.40). In patients with HF, the risk reduction for first HHF was similar for those with reduced EF ≤45% versus preserved EF >45% or unknown. However, in the overall population, the risk reduction tended to be greater for those with EF ≤45% (HR, 0.48 [95% CI, 0.30-0.76]) versus EF >45% (HR, 0.86 [95% CI, 0.58-1.29]). Effect on risk for first HHF was consistent across most subgroups, but greater benefit of ertugliflozin was observed in 3 populations: baseline estimated glomerular filtration rate <60 mL·min-1·1.73 m-2, albuminuria, and diuretic use (each P interaction <0.05). Ertugliflozin reduced total events of HHF (rate ratio, 0.70 [95% CI, 0.56-0.87]) and total HHF/CV death (rate ratio, 0.83 [95% CI, 0.72-0.96]). In patients with type 2 diabetes mellitus, ertugliflozin reduced the risk for first and total HHF and total HHF/CV death, adding further support for the use of sodium-glucose cotransporter 2 inhibitors in primary and secondary prevention of HHF. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01986881.