If you smoke now or quit in the last 15 years, one yearly scan may help find lung cancer early, when the outlook is better. The scan is called a low-dose CT. The Great American Smokeout is Thursday, November 19, a good day to check whether you qualify and to start a quit plan.
Who qualifies
The U.S. Preventive Services Task Force, a national panel of medical experts, recommends a yearly low-dose CT scan for adults who meet all three of these:
- Age 50 to 80
- A smoking history of at least 20 pack-years
- Smoke now, or quit within the past 15 years
The panel published this recommendation on March 9, 2021, with a grade B (the grade shows how strongly the panel recommends it). Screening is for people with no symptoms of lung cancer.
How to figure out pack-years
Pack-years measure how much you have smoked over time: packs a day times years smoked. One pack is 20 cigarettes. For example:
- 1 pack a day for 20 years = 20 pack-years
- 2 packs a day for 10 years = 20 pack-years
- Half a pack a day for 30 years = 15 pack-years
If your smoking changed over the years, your provider can help you add it up.
When screening stops
The panel says to stop once you have gone 15 years without smoking. Screening also stops if another health problem greatly shortens your expected lifespan, or if you could not have, or would not want, lung surgery to treat a cancer.
What screening can and cannot do
In large studies the panel reviewed, low-dose CT screening lowered deaths from lung cancer. In the National Lung Screening Trial, the drop was 16% with longer follow-up. That is a relative reduction: the risk of dying from lung cancer was 16% lower than in the comparison group, not 16 out of every 100 people. Early-stage lung cancer has a better outlook than cancer found later.
Screening also has trade-offs. Many scans find spots that turn out not to be cancer. These are called false positives. In that trial, about 1 in 4 people (26.3%) had a false positive at the first scan. Checking one can lead to more tests, sometimes a biopsy or surgery, though complications are uncommon. Screening can also find cancers that would never have caused harm, which is called overdiagnosis. A low-dose CT uses a small amount of radiation, about 0.65 to 2.36 mSv (millisieverts, a unit of radiation dose). That is less than the roughly 2.4 mSv people in the U.S. get from natural background radiation each year.
That is why the panel says you and your provider should talk through the benefits, limits and harms before you start. Medicare requires a visit like this before your first scan.
What insurance usually covers
Lung cancer screening for adults 50 to 80 at high risk is on HealthCare.gov's list of preventive services that Marketplace plans and many other plans must cover without a copay from an in-network provider, even before you meet your deductible. HealthCare.gov notes that $0 cost is not guaranteed in every case, so check with your plan. Medicare Part B covers a yearly low-dose CT for people 50 to 77 who have no symptoms, have at least 20 pack-years, and smoke now or quit within the last 15 years. Your provider must order it.
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Screening does not replace quitting
The panel says screening does not prevent most lung cancer deaths, so quitting is still essential. The American Cancer Society says counseling and medicine can double or even triple your chances of quitting. Make the Great American Smokeout your day one. Read how varenicline, bupropion and nicotine replacement compare, and what helps people quit vaping, dip or chew.
The South Carolina Department of Public Health says its SC Tobacco Quitline offers free quit support 24/7, whatever your insurance. Call 1-800-QUIT-NOW, text READY to 34191 or visit quitnowsc.org.
A question to bring to your next visit
"Based on my smoking history, do I qualify for a yearly low-dose CT scan?"
Lung cancer screening at Hope Integrative Medicine
Our primary care team can add up your pack-years, talk through the benefits and harms with you, order your scan at an imaging center you choose and go over the results. We can also help you quit with medicine and follow-up. Preventive visits are in person at our West Ashley office. New patients are often able to be scheduled within a week of requesting an appointment. Request an appointment.
Sources: U.S. Preventive Services Task Force, Lung Cancer: Screening (2021); Medicare.gov, Lung Cancer Screenings; HealthCare.gov, Preventive Care Benefits for Adults; American Cancer Society, Great American Smokeout; South Carolina Department of Public Health, SC Tobacco Quitline (August 10, 2026).
This article is general information, not medical advice, and does not create a patient–provider relationship. Every situation is different, so see a provider who can evaluate yours and develop a plan of care. Any medication discussed here may not be right for you: the right choice depends on your diagnoses, other health conditions and current medicines, so take medication only as directed by the provider managing your care. If you are ever in doubt about an emergency, call 911 or go to the nearest emergency room.
Frequently Asked Questions
The U.S. Preventive Services Task Force recommends a yearly low-dose CT scan for adults 50 to 80 with a 20 pack-year smoking history who smoke now or quit within the past 15 years.
Multiply the packs you smoked a day by the number of years you smoked. One pack a day for 20 years, or 2 packs a day for 10 years, both equal 20 pack-years.
Medicare Part B covers a yearly low-dose CT for people 50 to 77 with no symptoms who have at least 20 pack-years and smoke now or quit within the last 15 years. Your provider must order it, and you meet with your provider before the first scan.
The U.S. Preventive Services Task Force says screening stops once a person has gone 15 years without smoking. Talk with your provider about your own history.
Many spots found on screening are not cancer. Checking one can mean more tests, and sometimes a biopsy or surgery, though complications are uncommon. Your provider will explain the next step.