Background: Over 3 million home health and personal care aides (HHA) provide essential support for adults with chronic illness, including the complex self-care needs of adults with HF. Self-efficacy has been shown to mediate HHAs’ preparedness for caregiving and contribution to HF self-care. The determinants of HHA self-efficacy are unknown. Aim: Identify the determinants of HHAs’ self-efficacy in contributing to HF self-care. Methods: Secondary analysis of a cross-sectional survey (n=328) that examined the influence of HHA characteristics on contributions to HF self-care. Self-efficacy in contributing to patient HF self-care was assessed using the 10-item Caregiver Self-Efficacy in Contributing to Self-Care Scale. Standardized scores range 0-100; scores ≥ 70 pts indicate adequate self-efficacy. Preparedness was assessed with the 8-item Caregiver Preparedness scale. Additional predictors included job satisfaction, HHA experience, prior HF training, and agency size. Participants were divided into two groups based on a self-efficacy cutoff score of 70 points: low self-efficacy (< 70 pts) vs adequate self-efficacy (≥ 70 pts). Poisson regression with robust standard errors, adjusted for sociodemographic variables, was used to estimate prevalence ratios with 95% confidence intervals (PR [95% CI]) to identify determinants of adequate self-efficacy. Results: HHAs with adequate self-efficacy came from smaller and medium sized agencies (92% vs 84%, p =.049), and cared for either fewer than 6 (78% vs 68%, p=.002 ) or > 10 HF patients (11% vs 8%, p=.002 ). They had at least some prior HF training (55% vs 17%, p <.001), felt better prepared for caregiving (4.55±0.50 vs 3.39±0.85, p <.001), and were more satisfied with their jobs (90% vs 77%, p =.003). In a fully adjusted model, significant determinants for adequate self-efficacy were length of employment (1.02 [1.00-1.03], p =.027), better preparation for caregiving (3.10 [2.42-3.96], p <.001), and more HF training (1.48 [1.20-1.84], p <.001). Conclusion: Preparation for caregiving and HF training were the strongest determinants of HHAs’ caregiving self-efficacy. Home care agencies and policy-makers can target these modifiable determinants to improve this workforces’ ability to care for HF patients.