Objective: Currently, two out of every 100,000 people develop Chronic Lymphocytic Leukemia (CLL) annually. Over 90% of cases are found in people who are older than 50 years of age. As the United States population ages over the next two decades significantly more patients with CLL are likely to be diagnosed resulting in increased spending on CLL. Methods: Prevalence estimates of CLL in various age cohorts from Surveillance Epidemiology and EndResults (SEER) data combined with population demographics from the United States Census Bureau are used to project the direct costs associated with CLL over the next two decades. Sensitivity analysis is conducted around all estimates to assess key model parameters. Results: In 2006, the average direct cost of treatment was estimated at $304 million this is estimated to increase to 333 million by 2010 and over 413 million in 2020; an increase of 27% in the numbers of individuals in need of treatment. These conservative cost estimates are based on changing demographic distributions and do not include increases in the costs of health care delivery, treatments or indirect costs. The total costs of CLL are expected to reach over 1.5 billion United States Dollars by the year 2020. Conclusion: This work reviews the literature on the economic costs associated with CLL and based on expected demographic changes to the United States population, identifies an area of increasing concern to health care policy makers and providers of clinical services to oncology patients.