On 10 November 2014, the Centers for Medicare and Medicaid Services (CMS) published a draft statement for public comment in favor of screening for lung cancer using low-dose computed tomography (LDCT). In the decision summary, CMS stated that the “evidence is sufficient to add a lung cancer screening counseling and shared decision making visit, and for appropriate beneficiaries, screening for lung cancer with. LDCT, once per year, as an additional preventive service benefit under Medicare” [1]. This benefit is for smokers with at least 30 pack-years, between 55 and 74 years of age, who were asymptomatic and were either still smoking or had quit within less than 15 years. With this decision, the transition from a successful prospective randomized clinical trial to public policy has been advanced. The debates over insurance coverage for LDCT screening over the past 3 years have highlighted the many variables that can influence screening. These include the prevalence of the disease, the public health impact of the disease, the ability to positively intervene in the disease if screened, a safe and accurate technology to screen, the cost of screening and the ability to significantly reduce the disease burden. Furthermore, each of these variables can change. Diseases can become more prevalent, as lung cancer has from the 1980s to the current time. Technology can improve, such as the development of LDCT to detect lung nodules. Technology could advance still further, to the future development of a breath test to screen for lung cancer. This is why it is important to understand the influences of each of these variables in order to properly judge the strengths and potential pitfalls of s creening for lung cancer at this point in history. A quick historical review of how we arrived to the November CMS decision is warranted. Small trials of lung cancer screening with chest x-ray started in the 1950s [2]. Large, prospective, randomized controlled trials comparing chest x-ray and sputum cytology were run in the 1970s and 1980s. The lack of success of these screening methods led many to conclude that lung cancer screening would never be practical, but things changed. The number of newly diagnosed cases of lung cancer doubled to 228,190 from the 1980s to 2013 [1]. Competing causes of lung nodules became less common. The technological