Study Objective: To assess the ability of a new iteration of the ESSURE insert (ESS505) to achieve short-term fallopian tube occlusion. Design: Prospective, single center, interventional cohort (Canadian Task Force classification II-1). Setting: Tertiary care hospital. Patients: Women scheduled to undergo hysterectomy. Intervention: Patients underwent placement of the ESS505 in the right fallopian tube and ESS305 (the commercially approved previous version of the device) in the left fallopian tube at 30 (n = 10), 60 (n = 10), or 90 (n = 10) days before a planned hysterectomy. Tubal occlusion was assessed via hysterosalpingography (HSG) both at the time of placement and just before hysterectomy. Ultrasound was used to evaluate acute device placement. Measurements and Main Results: Thirty-five women (mean age, 39.7 years) were enrolled from July 2012 to January 2013, and 30 underwent both ESSURE placement and scheduled hysterectomy. Mean (SD) placement time for the ESS305 and ESS505 devices was 1.4 (0.65) minutes and 1.3 (0.42) minutes, respectively (p = .36). At 1 hour after ESS505 placement, 29 of 30 tubes (97%) exhibited complete occlusion at HSG, compared with only 4 of 30 tubes (13%) after ESS305 placement (p < .001 for difference in occlusion rates). At hysterectomy, the tubal occlusion rate was high in both groups: 97% for ESS505 and 100% for ESS305 tubes. High occlusion rates were observed in each of the 3 duration groups (30, 60, and 90 days). Five women experienced only minor adverse effects. Conclusion: ESS505, a modification to the commercially available ESS305 designed to cause immediate tubal occlusion, demonstrated a high rate of both immediate-term and intermediate-term tubal occlusion. Early tubal occlusion may obviate the need for interim alternative contraceptive methods after ESSURE placement. (C) 2014 AAGL. All rights reserved.