Postsale customer engagement is essential to retain B2B customers, grow existing accounts, and create advocates. Before an organization can plan the detailed interactions that maximize value for the customer and company, customer-facing functions must agree on what customers expect and what the company must do, from early-stage onboarding through product usage, renewal, expansion, and advocacy. In this report, we outline the Forrester Postsale Customer Lifecycle Framework, which customer-facing teams should use to strategize and plan programs around the four corresponding phases of the customer lifecycle and opportunity lifecycle.