There are several sets of guidelines, including the ones outlined below, to help determine who should be screened by LDCT for lung cancer. These guidelines are primarily based on active (current or prior) tobacco exposure. The guidelines have been established in large part from the results of the National Lung Screening Trial (NLST). They are very similar, with the differences primarily related to the role of screening for the oldest patients and risk factors other than smoking. All of the patients who are recommended for screening are considered to be at high risk for developing lung cancer but do not currently have any symptoms to suggest that they do have lung cancer. Patients should discuss these guidelines with their doctor and understand the risks and benefits before undergoing LDCT screening.

The guidelines from the US Preventive Services Task Force (USPSTF) include annual screening with LDCT in adults who:

  • Are aged 50 to 80 years and
  • Have a 20 pack-year smoking history and
  • Currently smoke or have quit within the past 15 years

    Pack-year graphic

The USPSTF recommends that lung cancer screening stop once a person:

  • Reaches 81 years of age or
  • Has not smoked in 15 years or
  • Develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery

The Centers for Medicare & Medicaid Services (CMS) covers costs associated with lung cancer screening based on the USPSTF criteria.

The guidelines from the National Comprehensive Cancer Network® (NCCN®) include annual screening with LDCT for individuals in two high-risk groups. These are adults who are either:

  • aged 55-77 years and
  • have smoked for 30 or more pack years and
  • are current smokers or quit smoking within the past 14 years


  • aged 50 years and over and
  • have smoked for 20 or more pack years and
  • have risk factors other than second-hand smoke

The NCCN® guidelines suggest follow-up screening. Usually the next LDCT will occur after one year, but this depends on the doctor's recommendation based on the screening test results.

The guidelines from the American College of Chest Physicians (CHEST®) include an annual screening with low-dose CT scans in adults who are:

  • aged 55-77 years and
  • have smoked 30 pack years or more and
  • either continue to smoke or have quit within the past 15 years

Those who do not meet the current screening criteria should speak with their doctor about the current status of their eligibility for screening. Note that health insurance, both government and private, typically does not cover LDCT screening for those who do not meet the USPSTF screening criteria.

The current criteria for lung cancer screening are based on active tobacco exposure. If you feel that you may have been exposed to other risk factors of lung cancer (read about risk factors here), you may choose to discuss the possibility of screening with your doctor.