This document describes a simple segmentation model for CRM implementations in professional services companies. It recommends keeping the segmentation plan simple with three account types (target, client, lapsed client), three contact types (existing client, inactive client, target), and tracking additional sub-segments of time and industry. The methodology defines the sales process as moving leads through an "up or out" process from target to active selling. It concludes with lessons learned around standardizing industry descriptions and contact/account/lead types during lead imports.