Abstract: OBJECTIVE: We assessed trends in novel cardiovascular medication utilization in US Veterans Affairs (VA) for angiotensin receptor-neprilysin inhibitors (ARNI), sodium-glucose cotransporter-2 Inhibitors (SGLT2i), and glucagon-like peptide-1 receptor agonists (GLP-1 RA). METHODS: We retrospectively identified cohorts from 114 VA hospitals with admission for prevalent 1) systolic heart failure (HF, N=82,375) or 2) coronary artery disease and diabetes (CAD+T2D, N=74,209). Site-level data for prevalent filled prescriptions were assessed at hospital admission, discharge, or within 6 months of discharge. Variability among sites was estimated with median odds ratios (mOR), and within-site Pearson correlations of utilization of each medication class were calculated. Site- and patient-level characteristics were compared by high-, mixed-, and low-utilizing sites. RESULTS: ARNI and SGTL2i use for HF increased from <5% to 20% and 21% respectively, while SGTL2i or GLP-1 RA use for CAD+T2D increased from <5% to 30% from 2017-2021. Adjusted mOR and 95% confidence intervals for ARNI, SGTL2i for HF, and SGTL2i or GLP-1 RA for CAD+T2D were 1.73 (1.64-1.91), 1.72 (1.59-1.81), and 1.53 (1.45-1.62), respectively. Utilization of each medication class correlated poorly with use of other novel classes (Pearson <0.38 for all). Higher patient volume, number of beds, and hospital complexity correlated with high-utilizing sites. CONCLUSION: Utilization of novel medications has increased over time but remains suboptimal for US Veterans with HF and CAD+T2D, with substantial site-level heterogeneity despite a universal medication formulary and low out-of-pocket costs for patients. Future work should include further characterization of hospital- and clinician-level practice patterns to serve as targets to increase implementation.