Approximately 20 Study Sites will participate over total 24 months. Study population will consist of adults age 22 or over, reporting overactive bladder (OAB) symptoms for at least 3 months.

Primary Study Objectives:

1. To assess efficacy of the StimRouter stimulation in improving OAB symptoms of urgency and frequency as measured by Patient Voiding Diary when targeting the posterior tibial nerve
2. To assess safety of the StimRouter therapy for the indication of OAB

Secondary Study Objective:

To evaluate efficacy of the StimRouter therapy in addressing urinary urge incontinence as measured by the Patient Voiding Diary

Study Design is prospective, multi-center, randomized, double-blinded

Primary Endpoint:

The primary efficacy endpoint will be the difference between the investigational and control groups in proportion of responders, where Responder is defined as having ≥50% improvement in average voiding frequency above the normal value of 8 (those returning to normal voiding based on 7-day average voids/leak episodes < 9, will be categorized as achieving half or more reduction) AND having ≥50% improvement in average number of moderate to severe urgency episodes, at approximately three months after programming.

Secondary Endpoint:

Secondary endpoint will be the difference between the investigational and control groups in proportion of patients with reduction by half or more in urinary urge incontinence as measured by the average number of urge incontinence episodes per day.

Approximately 180 subjects will be enrolled in the Percutaneous Tibial Nerve Stimulation (PTNS) for Overactive Bladder study. After signing the informed consent and completing the screening visit, eligible candidates will be asked to (1) stop any OAB medications (including but not limited to anti-muscarinic medication or tricyclic antidepressants (TCA) as well as stabilize dosage and frequency of any concomitant medications for 3 weeks, if applicable, and then (2) complete a daily Patient Voiding Diary for 7 days .

Subjects will then return to the office for baseline review. If all screening and baseline criteria are met, the subject will be enrolled, randomized in a 1:1 ratio into either the "control group" or the "investigational group" and scheduled for implant with the StimRouter device.

After approximately 3 weeks for healing post-implant, study participants will be programmed according to their randomization assignment. All subjects will be instructed to apply stimulation at least 3 days/week for at least 30 minutes/day (i.e., the minimum protocol requirements for device use) for 6 months and to apply stimulation when they anticipate OAB events. Patient Voiding Diaries will be completed by the participants for 7 days prior to each follow-up visit and provided to the office at each follow-up visit. Follow-up visits will occur at Month 1, Month 2, Month 3, Month 5 and Month 6. Each follow-up visit will include the review of subject voiding diaries and the completion of other subject questionnaires for measuring OAB and quality of life assessments. Final follow-up evaluations for all subjects will occur at Month 6.

Inclusion Criteria:

1. Male or female age ≥22 years and competent to provide consent
2. Minimum 3 months of self-reported OAB symptoms
3. A mean score of ≥4.0 on the OAB-q symptom questions 1-8
4. Diagnosis of OAB with Overactive Bladder Symptom Score (OABSS) ≥ 8.0
5. Average urinary frequency of ≥ 10 daily voids associated with urgency
6. Able to tolerate and sense tibial nerve stimulation
7. Willing to discontinue OAB and/or tricyclic antidepressant (TCA) medications for 3 weeks prior to the implant and for the entire study period and not to change dosages/frequency of all others for 3 weeks prior to the implant
8. Failed/inadequate response to first- and second-line therapy for OAB
9. Body mass index (BMI) < 31 or investigator does not expect BMI to interfere with ability to place the implant or negatively impact healing at implant site
10. Able to toilet self and have and maintain good personal hygiene
11. Able to utilize the StimRouter system independently
12. Negative urine dipstick result (no UTI detected)
13. If female of child-bearing age, willing to use a medically-acceptable method of contraception for the duration of the study (e.g. oral contraceptives, condoms, shot, patch, etc.)
14. Able to provide clear, thoughtful responses to questions and questionnaires
15. Willing to visit office for device programming and clinical evaluations at 1, 2, 3, 5 and 6 months after starting external device usage
16. Willing to complete a Patient Voiding Diary for 7 consecutive days prior to implant and 7 consecutive days before each follow-up visit, with moderate to severe urge component at Baseline

Exclusion Criteria:

1. Neurogenic bladder
2. Urinary tract mechanical obstruction including but not limited to Benign Prostatic Hyperplasia (BPH), treated or untreated, with ongoing significant obstruction
3. Treatment of bladder or pelvic floor dysfunction with botulinum toxin (Botox ®) or surgery in past 12 months
4. Urinary tract, bladder or vaginal infection or inflammation
5. More than minimal level of stress incontinence or mixed incontinence with stress component likely to confound study outcome
6. Type I diabetes or uncontrolled Type II diabetes
7. Allergy to local anesthetic or adhesives
8. Bleeding disorder or on an anticoagulant that cannot be stopped for 3 days before the implant
9. Pregnant, lactating, planning to become pregnant, given birth in the past 12 months, or female of child-bearing potential and not practicing a medically-approved method of birth control
10. Skin lesions or compromised skin at the implant or stimulation site
11. Use of investigational drug or device therapy or participation in any study involving or impacting gynecologic, urinary or renal function within past 4 weeks
12. Implanted neurostimulator, pacemaker, or defibrillator
13. Current use of TENS in pelvic region, back or leg
14. Current or prior use of electrical stimulation therapy for OAB (e.g. PTNS, sacral nerve stimulation, pelvic floor muscle stimulation or biofeedback)
15. Metallic implant below knee, within 6 inches of proposed site for implanted lead
16. Prior vaginal mesh or similar surgery that has not abolished stress incontinence, intravaginal pessaries, or other evidence of stress incontinence significant enough to confound study
17. Requirement for serial MRIs
18. Presence of a documented condition or abnormality that could compromise the safety of the patient
19. Life expectancy of less than 1 year

The implanting investigator, the study subjects, and the individuals who assess the outcome measures for each subject will be blinded to the subjects' randomization groups. Each study site's programmers will be unblinded to the randomization assignment and will receive each subject's randomization assignment. The programmers will then set the stimulation parameters and train the subjects on device use.