This is a retrospective-prospective study design. Patients who completed treatment approximately 3 years (range of 2-4 years) at time of IRB approval of this study will be identified and any existing data in the patient's record will be collected in addition to conducting office visits for long-term follow-up. The study will include 2 parts:
1. Retrospective chart review: Collect data from patient records who completed treatment a minimum of 2 years prior to study onset and determine the feasibility of doing a matched pair cohort study comparison of eBx versus Mohs surgery. The history, demographic and treatment data will be retrospectively collected from up to 320 subjects previously treated with eBx for the treatment of NMSC and up to 320 subjects previously treated with Mohs surgery for the treatment of NMSC.
2. Prospective Follow-up: Patients will return for long-term follow-up visits for the investigators to assess the lesion site, document absence of recurrence/ absence of recurrence, toxicities, and collect patient reported outcomes.
