Primary Inclusion Criteria:  Subjects 18 years of age or older Have a diagnosis for at least 6 months of OAB No OAB pharmacotherapy for 2 weeks prior to the baseline voiding diary Willing and able to accurately complete study diaries, questionnaires, attend visits, operate the system and comply with the study protocol Willing and able to provide signed and dated informed consent  Primary Exclusion Criteria:  Have neurological conditions such as multiple sclerosis, clinically significant peripheral neuropathy or spinal cord injury Severe uncontrolled diabetes History of urinary retention within the previous 6 months Current symptomatic urinary tract infection Have primary stress incontinence or mixed incontinence where the stress component overrides the urge component Current urinary tract mechanical obstruction Have knowledge of planned magnetic resonance imaging (MRIs) or diathermy History of a prior implantable tibial neuromodulation system Skin lesions or compromised skin integrity at the implant site Anatomical defects, clinically significant edema or previous surgeries which precludes use of the device Previous pelvic floor surgery in the last 6 months Women who are pregnant or planning to become pregnant Characteristics indicating a poor understanding of the study or characteristics that indicate the subject may have poor compliance with the study protocol requirements. Any subject who is considered to be part of a vulnerable patient population. Concurrent participation in another clinical study that may add additional safety risks and/or confound study results.** **Subjects in concurrent studies can only be enrolled with permission from Medtronic.  Contact Medtronic's study manager to determine if the subject can be enrolled in both studies.