The consumer operated and oriented plans (CO-OPs) created by the Patient Protection and Affordable Care Act (PPACA) will soon be the newest entrants in the health insurance marketplace. However, they are the next in a long history of entities aiming to sustain competition and innovation in the provision of prepaid healthcare. A careful review of the successes and failures of HMOs and health insurers that have come before can provide key insights into the challenges that CO-OPs face in creating, growing, and sustaining a plan. CO-OP managers can learn from this history and gain valuable insights that will help them formulate strategies on what to do—and what not to do—to build a viable, thriving, and competitive health plan.