Portfolio marketing is an essential B2B function that is responsible for understanding market segments and buyer needs for the purpose of identifying opportunities and bringing offerings to market that help an organization achieve its growth potential. Despite portfolio marketing’s importance to success, leaders often struggle to build a balanced, scalable, and aligned function focused on delivering business impact. In this report, we introduce the Forrester B2B Marketing Ecosystem Model For Portfolio Marketing and define the core components required to build a strategic, best-in-class portfolio marketing function.