Inclusion Criteria:  Female patients > 18 years old at UAB facilities with refractory urgency urinary incontinence that have failed first line and second line treatments Ability to consent Ability to complete all study related items and interviews  Exclusion Criteria:  Patients with a history of any known or determined urinary retention or urinary tract obstruction PVR > 150 ml in clinic prior to the start of PTNS History of bladder augmentation surgery Patients who are pregnant or who have the suspicion of pregnancy Uncontrolled hypertension Hypersensitivity to mirabegron Superficial and/or deep skin infection where PTNS intervention is required Spinal cord injury or clinically significant neurological disorders known to affect urgency urinary incontinence Bleeding diathesis Failure of previous third line treatment options such as sacral neuromodulation, PTNS, or Botox Pacemaker, implantable defibrillator Current use of Interstim sacral nerve stimulator or TENS in the pelvic region, back, or legs Coagulopathy Chronic swollen, infected, inflamed skin or skin eruptions (e.g., phlebitis, thrombophlebitis, varicose veins) in the region where the PTNS needles or surface electrodes would be placed Metal implant in foot/toes near TENS electrode location Marked sensory deficit (numbness) of feet or ankles in the region where the PTNS needles or surface electrodes would be placed Currently pregnant or planning to become pregnant during the course of the study Unwilling to use acceptable form of contraceptive if the participant is of childbearing potential Unable or unwilling to complete the 3-day bladder diary Visual impairment prohibiting reading the paper diary Inability to provide informed consent, complete questionnaires independently, or to attend intervention sessions Unable to speak, read, or write in English