Only a Quarter of Eligible People Get a Free Lung Screening Scan. How to Get Yours in 6 Steps

The scan may cost nothing, but getting it covered involves some eligibility math and one appointment you have to arrange first.

If you smoked for years, Medicare will pay for an annual scan that can detect lung cancer before it grows large. If your provider accepts Medicare assignment, the scan costs nothing.

Even so, most people who qualify for screening are not getting it.

According to a University of Kentucky Markey Cancer Center study published in JAMA Internal Medicine, 24.5% of adults who met federal screening guidelines were up to date on their scans in 2024.

That works out to about 1 in 4. The rate improved from 2022, but Todd Burus, an assistant professor in the UK College of Medicine and one of the researchers, said, “We still have a long way to go.”

That matters because lung cancer kills more Americans than any other cancer, according to the Centers for Disease Control and Prevention.

And I understand why many of the other 3 in 4 never get around to it: the rules are picky, the math is tricky, and Medicare requires one extra step before the first scan. Here’s how to navigate it.

1. Check whether you qualify

Medicare Part B covers one low-dose CT lung scan each year if you meet every one of these conditions, according to Medicare.gov:

• You are 50 to 77 years old.
• You have no symptoms of lung cancer.
• You currently smoke, or you quit within the past 15 years.
• You have a smoking history of at least 20 pack-years.
• Your doctor or another provider orders the scan.

There is one catch: Medicare and the experts do not line up exactly. The U.S. Preventive Services Task Force recommends yearly screening for people ages 50 to 80 with the same smoking history, while Medicare’s coverage stops at 77.

So if you are 78 to 80, the task force says screening is appropriate, but Medicare’s screening benefit does not apply. Talk with your doctor about that difference before scheduling anything.

Also note the symptom rule. This is meant for people who feel fine. If you have a persistent cough or other concerning signs, that is a medical visit, not a screening appointment.

2. Calculate your pack-years

This is where many people get stuck. A pack-year does not mean a year you smoked. It means one pack a day for one year, with a pack defined as 20 cigarettes, according to Medicare’s rules.

The formula is simple: packs per day multiplied by years smoked. The total must be 20 or more.

Examples:

• One pack a day for 20 years: 1 x 20 = 20 pack-years. You qualify.
• Half a pack a day for 40 years: 0.5 x 40 = 20 pack-years. You qualify.
• Two packs a day for 10 years: 2 x 10 = 20 pack-years. You qualify.
• One and a half packs a day for 15 years: 1.5 x 15 = 22.5 pack-years. You qualify.
• Half a pack a day for 30 years: 0.5 x 30 = 15 pack-years. You do not qualify.

If you checked years ago and missed the cutoff, take another look. Medicare used to require 30 pack-years, but it lowered the threshold to 20 in 2022, according to a Centers for Medicare and Medicaid Services notice to providers.

Then consider the quit date. Coverage depends not just on how much you smoked, but also on how long it has been since you stopped. If you quit at 60, you generally have until about 75 before you age out of the 15-year window.

3. Schedule the counseling visit before the scan

Here is the extra step. Before your first lung scan, Medicare requires a separate visit with your provider to review the pros and cons and decide whether screening makes sense for you.

Under Medicare’s national coverage rules, that visit must include a shared decision-making discussion using at least one decision aid, along with counseling about annual follow-up scans. Current smokers must also get information about quitting help, while former smokers should be encouraged to stay smoke-free.

This is the point where many people stop. The scan cannot happen until the discussion does.

Call your doctor and ask specifically for a lung cancer screening counseling and shared decision-making visit. At the same time, ask for the scan order.

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4. Find out what it will cost

The screening itself costs $0 if your provider accepts Medicare assignment, according to Medicare.gov.

So ask before you book: “Do you accept Medicare assignment?” That 10-second question can be the difference between a free scan and a bill.

Also ask what happens if the scan shows something unusual. Follow-up tests are a separate issue, so check what Medicare will cover before agreeing to additional procedures.

5. Be ready for a false alarm

Low-dose CT scans are highly sensitive. They detect many small spots in the lungs, and most of them are not cancer.

In the National Lung Screening Trial, the major federal study published in 2011 that demonstrated the scans’ value, 96.4% of positive low-dose CT results turned out to be false alarms, according to the National Cancer Institute.

The task force says about 26% of first-round scans in that trial were false positives, and it lists the chance of extra testing and procedures as one of the harms of screening.

The good news, according to the NCI, is that follow-up in that trial was usually just additional imaging. Only a small number of people needed invasive procedures. When biopsies are needed, possible complications include partial lung collapse, bleeding and infection.

That is why the counseling visit matters: you should go in expecting that a callback is common.

Screening is not meant to continue forever, either. The task force says to stop once you have gone 15 years without smoking or if a health problem significantly limits life expectancy.

Not every test is worth doing at every age, as we noted in “7 Medical Tests and Treatments You Might Be Smart to Skip After 65.”

6. If you never smoked, test your home for radon

None of this Medicare screening coverage applies if you never smoked. But that does not mean your lungs are risk-free.

According to the Environmental Protection Agency, radon gas is the leading cause of lung cancer among people who do not smoke. Overall, it ranks second behind smoking.

The EPA attributes about 21,000 lung cancer deaths a year to radon. Roughly 2,900 of those are among people who never smoked.

The solution starts with testing. The EPA says to fix your home if the level is 4 picocuries per liter or higher.

Bottom line

In the federal trial, people screened with low-dose CT had about 15% to 20% fewer lung cancer deaths than people screened with chest X-rays, according to the NCI. Medicare will cover the scan at no charge if you qualify and use a provider who accepts assignment.

What I would do now: run your pack-year calculation. If you reach 20 and meet the age and quit-date limits, call your doctor, request the counseling visit, and get the order.

Lung cancer screening is one of the free Medicare preventive services that can save your life. If you are already paying Medicare premiums, use the benefits available to you.

And as always, this is not medical advice. Talk with your doctor about whether screening is right for you.