Screening check
Lung cancer screening: do I qualify?
A yearly low-dose CT scan is recommended for some adults who smoke or used to smoke. Whether you qualify depends on your age, how much you smoked and, for one guideline, when you quit.
Your smoking history
Rough numbers are fine. Nothing you enter leaves this page.
What you will see
Your pack-years, and whether you meet the USPSTF and American Cancer Society screening criteria.
Educational only, not medical advice. Screening decisions are made with your doctor.
Source
US Preventive Services Task Force, 2021 recommendation (grade B). American Cancer Society, 2023 guideline update.
Validated in
Adults without symptoms of lung cancer. Based on screening trials such as the National Lung Screening Trial and on modeling studies.
Limits
Not for people with symptoms. Does not weigh other health problems that may make screening or surgery a poor fit. It checks the published criteria only, not your personal cancer risk.
Who should be screened
The USPSTF recommends a low-dose CT scan every year for adults aged 50 to 80 who have a 20 pack-year smoking history and who smoke now or quit within the past 15 years (USPSTF 2021). It advises stopping once a person has not smoked for 15 years, or develops a health problem that substantially limits life expectancy or the ability or willingness to have lung surgery (USPSTF 2021).
The American Cancer Society's 2023 guideline uses the same age range and the same 20 pack-years, but drops the 15-year limit: people who used to smoke stay eligible however long ago they quit (ACS 2023).
| USPSTF 2021 | American Cancer Society 2023 | |
|---|---|---|
| Age | 50 to 80 | 50 to 80 |
| Smoking history | 20 pack-years or more | 20 pack-years or more |
| Quit | Within the past 15 years, or still smoking | Any time, or still smoking |
| Test | Low-dose CT, yearly | Low-dose CT, yearly |
How to work out pack-years
One pack-year means smoking an average of 20 cigarettes, one pack, a day for a year (USPSTF 2021). Multiply the packs you smoked a day by the number of years you smoked:
- 1 pack a day for 20 years = 20 pack-years
- Half a pack (10 cigarettes) a day for 30 years = 15 pack-years
- 2 packs a day for 10 years = 20 pack-years
If your smoking changed over time, add up each period separately. A best estimate is fine for a conversation with your doctor.
What screening can do
In the National Lung Screening Trial, more than 53,000 adults with a heavy smoking history were screened with either low-dose CT or chest X-ray. The CT group had 20% fewer deaths from lung cancer (NLST 2011). The USPSTF's modeling estimated that screening under its 2021 criteria would cut lung cancer deaths by 13% and avert 503 lung cancer deaths per 100,000 people screened, compared with no screening (USPSTF 2021).
The downsides
Screening has real harms, which is why it is offered only to people at higher risk. In the trials the USPSTF reviewed, false-positive rates ranged from 7.1% to 27.2%, meaning many people were called back for more scans or tests and did not have cancer (USPSTF 2021). About 6% of screen-detected lung cancers were judged to be overdiagnosis: cancers that would never have caused harm (USPSTF 2021). The scans also carry a small radiation dose (USPSTF 2021). These are worth talking through with your doctor before starting.
Quitting smoking matters more than any scan. Screening does not replace it.
Common questions
Does screening work if I quit 20 years ago?
Under the USPSTF criteria you would no longer qualify, because the limit is 15 years since quitting (USPSTF 2021). Under the American Cancer Society guideline you would still qualify if you are 50 to 80 with at least 20 pack-years (ACS 2023). Ask your doctor which applies to your coverage.
I have a cough or chest pain. Should I use this?
No. Screening is for people without symptoms. A cough that will not go away, coughing up blood or unexplained weight loss are reasons to see a doctor now.
Is a chest X-ray the same thing?
No. The recommended test is a low-dose CT scan (USPSTF 2021). In the National Lung Screening Trial, low-dose CT was compared directly against chest X-ray (NLST 2011).
Also see the quit smoking help check, the COPD screening check, the colon cancer screening age check and the abdominal aortic aneurysm screening check, also based on smoking history.
Sources
- US Preventive Services Task Force. Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(10):962-970. www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening
- Wolf AMD, Oeffinger KC, Shih TY, et al. Screening for lung cancer: 2023 guideline update from the American Cancer Society. CA Cancer J Clin. 2024;74(1):50-81. doi.org/10.3322/caac.21811
- National Lung Screening Trial Research Team. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365(5):395-409. doi.org/10.1056/NEJMoa1102873
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-10-30. Spotted an error? See About.