This document presents the business case for a national mentoring program for evaluators in Canada. It summarizes the objectives, background, methodology, findings and conclusions of the Core Mentoring Working Group. There is a demonstrated demand for mentoring among evaluators based on multiple surveys. The advantages of mentoring for both mentees and mentors were identified. An effective program would have various dimensions such as different types of mentoring relationships, effective matching processes, and support structures. Issues such as the mentoring lifecycle, risks, and costs need to be considered when developing the program. The working group proposes a national online mentoring service and outlines next steps to pilot and implement the program.