BACKGROUND: Safety and efficacy endpoints for the single-arm, multicenter, open-label pivotal study, CONtrolled Focal Fibrous Band Release Method (CONFFIRM) [NCT04743635] assessing Targeted Verifiable Subcision (TVS) for the treatment of cellulite were met at 3 months post-procedure and have been published. Final, 12 month data describing durability of treatment effect and safety are presented here for the first time. OBJECTIVES: To evaluate safety and efficacy out to 12 months of initial treatment for a single TVS procedure performed using the Avéli device (Revelle Aesthetics, Inc., Mountain View, CA) to treat cellulite on the buttock and thigh areas of adult females. METHODS: Effectiveness was determined by 3 independent physicians using the Cellulite Severity Scale (CSS) and Global Aesthetic Improvement Scale (GAIS) to assess improvement of baseline photographs when compared to 3-, 6- and 12-months posttreatment photographs. Blinded participant-reported outcomes (PROs) and safety evaluations were also performed at all post-procedure time points. RESULTS: Clinically significant improvement in primary endpoint CSS scores were sustained out to 1 year, improving by 1.50 (p < .0001) at 3 months, 1.54 points at 6 months and 1.48 points at 12 months. Adverse events were mild and mostly resolved by the 12 month visit. CONCLUSIONS: A single TVS treatment has durable efficacy and safety in reducing cellulite on the buttocks and thighs of women with moderate to severe cellulite out to 12 months posttreatment.