BACKGROUND: The Natrelle Style 410 shaped, form-stable silicone gel implant (Allergan, Inc; Irvine, California) has been the subject of a pivotal study that supports potential US Food and Drug Administration approval of the device. The 3-year results of this study were reported previously. OBJECTIVES: The authors update the safety and effectiveness findings for the Natrelle Style 410 implants through 6 years of study. METHODS: This prospective, nonrandomized, multicenter study included 941 patients (492 primary augmentations, 156 revision-augmentations, 225 primary reconstructions, and 68 revision-reconstructions). Since the original 3-year report, follow-up visits have been conducted annually. Kaplan-Meier risk rates were calculated for local complications, reoperations, and explantations. One-third of the subjects were enrolled in the magnetic resonance imaging (MRI) cohort and underwent biannual MRI rupture screening. Effectiveness was measured by subject satisfaction on a 5-point scale. RESULTS: As expected after breast implantation, capsular contracture (CC) was one of the most common complications, with 6-year risk rates of 4.6% for augmentation, 6.9% for revision-augmentation, 10.7% for reconstruction, and 18.3% for revision-reconstruction. The rates for CC among augmentations and revision-augmentations were significantly lower with the Natrelle 410 implants than with other standard gel implants. The rupture rate (confirmed plus suspected) across all cohorts was 6.4% by subject and 3.8% by implant. The most common reasons for reoperation were style or size change (augmentation), implant malposition (revision-augmentation), scarring (reconstruction), and CC (revision-reconstruction). The satisfaction rate exceeded 80% in all cohorts. CONCLUSIONS: These fifth-generation, form-stable implants represent another option to achieve desired aesthetic outcomes with minimal complications.