During Annual Enrollment Period (AEP), health plan marketing departments spare no effort to meet organizational goals for member acquisition, revenue, and market share. Yet compressed schedules, tight budgets, and evolving market conditions make it difficult to adopt new strategies and tactics that enhance efficiency and acquisition ROI. Industry leaders recognize that AEP marketing must become more science – leveraging nuanced customer segmentation models, and highly targeted marketing tactics – and less guesswork. This paper introduces AEP Precision Marketing: a six-step, data-driven process that health plans can use to develop and direct highly structured and customer-responsive AEP campaigns. This approach allows market and performance knowledge to be captured and shared across the organization, making it smarter, more efficient, and more competitive.