This is a multi-center, investigator blinded, randomized study designed to assess the efficacy, duration of effect, safety and tolerability of Luma Light System for plaque psoriasis. Two selected areas to be treated will be determined by the Investigator at Baseline. Excluded areas include the palms, the soles of the feet, the intertriginous areas, the knee, the elbow, the face and the scalp. Target Plaque Assessment (TPA), tolerability assessment and any adverse events (AEs) will be obtained at each visit. The subject may use topical prescriptions (steroids, vitamin D analogs, retinoids, etc.) for non-target plaques during this trial with approval of the investigator as long as they keep a 1" border around the target plaques where no prescription topical is applied. Any treatment that is not part of the trial that the subject uses for psoriasis should be noted in the subject's file.