Lung Cancer Screening: The Yearly Scan Most Eligible People Miss

Here is a number worth a second look: 18%. That’s the share of eligible adults ages 50 to 79 who said they’d had a lung cancer screening scan in the past year, according to a study of 2022 national survey data published in 2024 in JAMA Internal Medicine. Among eligible adults 70 to 79, it was about 27%.

That leaves most people who qualify without a recent scan that could help find lung cancer early. And lung cancer is the leading cause of cancer death in the United States, according to the National Cancer Institute (NCI).

If you smoke now, or used to, here is what to know.

What the Scan Can Do

Lung cancer screening uses a low-dose CT scan, which takes a series of detailed pictures of the inside of your chest with a small amount of radiation.

The largest trial to date, the National Lung Screening Trial, enrolled more than 53,000 people with a history of heavy smoking. According to NCI, people screened with low-dose CT had a 15% to 20% lower risk of dying from lung cancer than people screened with standard chest X-rays. That worked out to about three fewer deaths for every 1,000 people screened over roughly seven years.

Screening is meant for people who feel fine. NCI notes that screening tests are given when you have no cancer symptoms. If you have symptoms that concern you, see your doctor now.

Who Should Get Screened

The U.S. Preventive Services Task Force recommends a yearly low-dose CT scan for adults who:

• Are 50 to 80 years old
• Have a smoking history of at least 20 “pack-years”
• Smoke now, or quit within the past 15 years

Pack-years are the average number of packs you smoked per day multiplied by the number of years you smoked. One pack a day for 20 years is 20 pack-years. So is two packs a day for 10 years.

The task force says screening should stop once you’ve gone 15 years without smoking, or if a health problem would seriously limit your life expectancy or your ability or willingness to have lung surgery.

What Medicare Covers

Medicare Part B covers a yearly lung cancer screening scan if you meet all of these conditions:

• You’re 50 to 77 years old.
• You don’t have signs or symptoms of lung cancer.
• You smoke now, or quit within the last 15 years.
• You have a smoking history of at least 20 pack-years.
• You get an order from your health care provider.

You pay nothing for the scan if your provider accepts Medicare assignment.

Note the age gap. Medicare covers screening through age 77, while the task force recommendation goes to 80. If you’re 78 to 80, Part B won’t pay for the scan, so ask about the cost first.

Before your first scan, Medicare requires a visit with your provider to talk through the benefits and risks and decide whether screening is right for you.

Know the Trade-Offs

That conversation matters, because screening has downsides too. The task force lists:

• False alarms. A scan can flag something that turns out not to be cancer, which can lead to more tests and sometimes to procedures that weren’t needed.
• Overdiagnosis. Screening can find cancers that may never have caused symptoms or become life-threatening. NCI notes it’s not clear how often this happens.
• Radiation. Each scan involves a small dose, and radiation exposure can raise cancer risk.
• Worry. An unclear or abnormal result can cause short-term stress and anxiety.

The task force concluded that for people who meet the criteria, yearly screening has a moderate net benefit, meaning the benefits outweigh the harms. That balance depends on screening the people at highest risk, and on careful reading and follow-up of scans. That’s why the eligibility rules are specific.

If You Smoke Now