Guideline-directed medical therapy (GDMT) has significantly improved outcomes in patients with heart failure with reduced ejection fraction (HFrEF). However, GDMT prescribing remains suboptimal. The purpose of this study was to survey cardiologists, internists, and pharmacists on their approach to GDMT prescribing. A survey containing 20 clinical vignettes of patients with HFrEF was answered by 127 cardiologists, 68 internists, and 89 pharmacists. Each vignette presented options for adjusting GDMT. Responses were dichotomized to the answer of interest. A mixed-effect model was used to calculate the odds of changing GDMT between pharmacists and physicians. Pharmacists were more likely to make changes to GDMT compared with internists (92.1% vs 82%; odds ratio [OR] 3.02 [1.50-6.06]; p=0.002). In medically-naïve patients, pharmacists were more likely to initiate beta-blockers than internists (45.4% vs 32.0%; OR 2.19 [1.00-4.79], p=0.049). Pharmacists were more likely than both internists and cardiologists to initiate mineralocorticoid receptor antagonists (34.4% vs 11.5%; OR 4.95 [2.41-10.18]; p<0.001 and 34.4% vs 13.9%; OR 3.95 [2.16-7.21]; p<0.001). Pharmacists were more likely than both internists and cardiologists to titrate beta-blockers (30.9% vs 16.4%; OR 3.15 [1.92-5.19]; p<0.001 and 30.9% vs 22.0%; OR 1.88 [0.18-2.87]; p=0.0030). Pharmacists were more likely than internists to titrate angiotensin receptor-neprilysin inhibitors (ARNI) (61.8% vs 34.1%; OR 3.54 [1.50-8.39]; p=0.004). The survey results show pharmacists were more likely to make any adjustments to GDMT than internists and cardiologists. Pharmacists prefer adding spironolactone and titrating beta-blockers compared with cardiologists and internists. Compared with only internists, pharmacists were more likely to initiate beta-blockers and titrate the dose of ARNI.