Abstract Introduction Hospitalizations for worsening heart failure (HF) represent an enormous public health and financial burden. Accordingly, select centers have developed outpatient worsening HF (WHF) management strategies focused on care in emergency departments (ED), observation units, or intravenous (IV) diuretic clinics. However, broad use of these outpatient strategies and the associated outcomes and healthcare costs remain unclear. Methods Among US Medicare beneficiaries age ≥65 years hospitalized for HF in the Get With The Guidelines Heart Failure registry 2010-2018, we identified patients with a post-discharge non-fatal WHF event. Patients were divided into 4 mutually exclusive groups defined by type of first post-discharge WHF event (HF hospitalization, ED visit with ED discharge, observation unit stay, and outpatient clinic visit with IV diuretics). Following each type of WHF event, mortality, home-time (days alive and out of any healthcare institution), and healthcare costs were compared over the subsequent 12-months. Costs of the initial WHF management strategy were also assessed. Results Among 181,827 patients hospitalized for HF, during the 12-months post-discharge, 83,971 (46.2%) survived with no WHF event, 36,697 (20.2%) died prior to a WHF event, and 61,159 (33.6%) had a WHF event. Of patients with a WHF event, 48,612 were managed with HF hospitalization (79.5%), 8,139 (13.3%) with an ED visit, 1,767 (2.9%) with an observation unit stay, and 2,641 (4.3%) with an outpatient IV diuretic visit. Compared with HF hospitalization, patients with WHF managed in the ED, observation unit, or IV diuretic clinic experienced lower subsequent mortality (Figure 1). Mean 12-month home-time was lowest following HF hospitalization (207 ± 144 days), intermediate following ED (238 ±136 days) and outpatient IV diuretic visits (252 ±128 days), and highest following observation unit stays (277 ± 125 days). For the initial WHF event, median (25th, 75th) total per-patient costs were highest for HF hospitalization and lowest for outpatient IV diuretic visits (Figure 2). Over the 12-months following the WHF event, median total per-patient costs were highest following outpatient IV diuretic visits, intermediate following HF hospitalization and ED stays, and lowest following observation unit stays. Conclusions In a nationwide analysis of older US adults, 1 in 5 episodes of recurrent WHF were exclusively managed as an outpatient within the ED, observation unit, or IV diuretic clinic. High rates of death and substantial reductions in home-time occurred following WHF regardless of inpatient or outpatient management, but were worse following HF hospitalization. Outpatient IV diuretic administration was the least expensive initial management strategy, but was associated with the highest per-patient costs over the subsequent 12 months.