This is a modified extension study to the SUmiT protocol UPC082008 (NCT00534521) to observe and evaluate long term therapy with PTNS on overactive bladder symptoms. Subjects must have completed the 12 weekly treatments of the original protocol, the 13 week follow up assessment, be randomized to the PTNS arm, and be considered a positive responder with moderate or marked improvement in the SUmiT Trial to be enrolled in this study. All consenting responders will continue with active PTNS therapy at an initially prescribed protocol for approximately 3 months followed by individualized symptom-based frequency of visits as determined by the subject along with their treating clinician, for up to a total of 33 months post initial 12-week therapy for a total of 3 years.