Background Nurse-led care supported by mobile health (mHealth) technologies offers a feasible strategy to strengthen heart failure (HF) management in resource-constrained settings. This study evaluated the impact of an mHealth-enabled, nurse-led collaborative care model on prescription of guideline-directed medical therapy (GDMT) at discharge among patients with heart failure with reduced ejection fraction (HFrEF) in India. Methods The TIME-HF study was a multicenter, open-label, cluster-randomized controlled trial conducted across 22 centers enrolling patients with HFrEF. Centers were randomized 1:1 to an intervention arm (11 centers; 755 patients) or enhanced usual care (11 centers; 752 patients). In the intervention arm, nurses used an mHealth application to review GDMT prescriptions and recommend treatment modifications to physicians. GDMT at discharge was assessed individually and using a composite score. Intervention effects were evaluated using multivariable mixed-effects logistic regression models. Results Participants were predominantly male (77.6%) with a mean age of 61.9 years (SD 12.1). Hypertension (56.1%), diabetes (62%), and chronic kidney disease (18.4%) were common comorbidities. Ischemic heart disease was the leading etiology (77.4%), and 48.8% were in NYHA class III/IV. Baseline characteristics were similar between groups. At discharge, 20% received all four GDMT components, with higher use in the intervention group than usual care (27% vs 13%, p