CT lung cancer screening can be more efficient when risk models are used to determine eligibility. However, detailed risk assessment requires time spent by a healthcare provider and may present a barrier to screening when resources are limited. Here, we developed a tool to identify ever-smokers with low probability of risk-based eligibility. We analyzed ever-smokers aged 50-80 in the representative 2015 US National Health Interview Survey. We defined ever-smokers with 6-year risk ≥1.3% by the 12-question PLCOm2012 model as screening-eligible. We considered that detailed risk assessment may be inefficient when the probability of eligibility is less than 5%. Accordingly, we used cross-tabulations of age, cigarettes-per-day, and quit-years to identify groups in whom risk assessment might be avoided. There are approximately 44,140,774 U.S. ever-smokers aged 50-80 who could consider detailed risk assessment. However, a simple decision-tree tool identified 22,293,477 ever-smokers (50.5%) who are less than 5% likely to be screening-eligible (Figure). This includes all those who smoke(d) less than 5 cigarettes-per-day. Over 1 year, approximately 103,512 lung cancers were predicted among eligible ever-smokers. If our tool were used, then 1,784 of these eligible cases (1.7%) would not undergo detailed risk assessment or screening. When resources are limited, a simple decision-tree tool could avoid detailed risk assessment for more than half of U.S. ever smokers aged 50-80, while still identifying 98.3% of eligible cases. Such a tool could be self-administered by patients in the waiting room or applied automatically to electronic health records to optimize use of provider time.