Subcision is a minor surgical procedure used for treating depressed acne scars. It stimulates collagen regrowth, which improves the appearance of depressions in the skin caused by acne lesions. Subcision is performed by numbing the area and using a special hypodermic needle inserted through a puncture in the skin surface to break up scar tissue. Most scars require a series of subcision treatments for significant improvement of the appearance of acne scars. Despite being surgical, this treatment is not covered by insurance because it is not medically necessary and is, therefore, considered a cosmetic (elective) treatment.