Background Treatment for worsening congestion with intravenous loop diuretics (IV-LD) in the ambulatory setting has become an increasingly common alternative to hospitalization for patients with HF. Little is known about the appropriate use of IV-LD in ambulatory HF patients. We report outcomes of an IV-LD dosing algorithm designed for ambulatory use. Methods We included consecutive patients treated for worsening HF at our ambulatory HF treatment unit. IV-LD doses were derived from the total daily oral loop diuretic dose: for those on 0-40 mg furosemide equivalent/day, 20 mg IV furosemide was given as a bolus (Low Dose); for >40-160 mg/day, the oral dose was given IV (Moderate Dose); for >160-300 mg/day, 200 mg IV was given as a bolus, with repeat at 1 hour if needed (High Dose); >300 mg/day, 200 mg IV with thiazide pretreatment and/or repeat 200 mg bolus as needed (Mega Dose). The Moderate, High and Mega Dose groups also received a 3-hour, 60 mg furosemide infusion. Efficacy outcomes were net fluid loss and net weight loss at 3 hours and 30-day HF hospitalization rate. Safety outcomes were serum creatinine rise > = 0.3 mg/dL (WRF) and serum potassium Results Between May 2013 and December 2017, 283 unique patients were treated in 448 episodes. Median age of the cohort was 69 (58-78) years, 108 (38%) were women, 176 (62%) had a HF hospitalization within the prior year and 138 (49%) had LVEF >40%. Net fluid loss (P-trend = 0.20) and weight loss (P-trend = 0.42) did not differ across IV-LD dosing groups (Figure). Hypokalemia was more common in the higher dose groups, but incident WRF was not (Figure). HF hospitalization at 30-days occurred in 8 (20%) Low Dose, 14 (18%) Moderate Dose, 3 (13%) High Dose and 54 (38%) Mega Dose patients (P-trend Conclusions Decongestion was successfully achieved with an ambulatory IV diuretic strategy across a broad spectrum of HF severity and maintenance loop diuretic doses. Outpatient IV-LD appears to be an effective strategy for deferring HF hospitalization in many advanced HF patients with worsening symptoms.