"I quit years ago, so I figured that chapter was closed." A lot of former smokers think the same thing. Quitting is a major win, but it doesn't erase the years your lungs spent around smoke.
If you're 50 to 80, have smoked at least 20 pack-years, and still smoke or quit within the past 15 years, the US Preventive Services Task Force recommends a yearly low-dose CT scan. Medicare uses a narrower age range for coverage, so check the details before scheduling.
- ✓Ages 50 to 80, 20 pack-years, and quitting within 15 years are key criteria.
- ✓Low-dose CT takes minutes and isn't painful.
- ✓Screening has benefits, false positives, and other trade-offs.
Who qualifies for a yearly lung scan
Start with your age, total pack-years, and time since quitting. The USPSTF recommendation covers adults ages 50 to 80 with at least 20 pack-years who currently smoke or quit within the past 15 years.
A pack-year measures smoking exposure. Use this math:
> Packs smoked per day × years smoked = pack-years
>
> 1 pack per day × 20 years = 20 pack-years
Two packs a day for 10 years also equals 20 pack-years. If you smoked less than a pack a day, add the fractions across the years. If you're unsure, write down the years and usual amount, then ask your doctor or a screening program to do the math with you.
Eligibility isn't an automatic order. Screening is for people without signs or symptoms of lung cancer who could undergo evaluation and treatment if a scan found something. Your doctor should discuss benefits, limits, and other health problems.
What happens in the scanner
A low-dose CT isn't the same as a chest X-ray. You lie on a table while an X-ray machine makes detailed lung pictures with a lower radiation dose than a standard chest CT. The CDC says the scan takes only a few minutes and isn't painful.
You may hold your breath briefly while images are taken. The appointment also covers your history and what happens if the radiologist sees a spot needing follow-up.
Screening has trade-offs. A scan can suggest cancer when none is present, leading to repeat imaging or invasive tests. It can find a cancer that would never have caused trouble, and repeated radiation carries a small risk. That's why the recommendation targets people at higher risk, not everyone who has ever smoked.
Why early detection matters
The American Lung Association says annual low-dose CT screening can reduce the lung cancer death rate by up to 20% by finding tumors earlier, when treatment may be more effective. That's a population-level benefit, not a guarantee for one person.
The national screening rate remains low. In the American Lung Association's 2025 State of Lung Cancer report, only 18.2% of people at high risk were screened. Rhode Island had the highest reported rate at 31.0%, while Wyoming had the lowest at 9.7%.
A scan can't undo past smoking, and it isn't a substitute for quitting. Screening is a tool, not a report card on the years behind you. The useful question is whether it makes sense now.
Why eligible people skip it
Some people assume quitting means lung cancer is no longer a concern. Others never hear "low-dose CT" from their doctor, worry about bad news, or don't know their pack-year history.
Transportation, cost, rural access, and confusing insurance rules create more barriers. If you're on Medicare, Part B covers an annual low-dose CT screening when you meet its conditions: age 50 to 77, no signs or symptoms, at least 20 pack-years, current smoking or quitting within the past 15 years, and an order from your doctor. Medicare says you pay nothing when the provider accepts assignment.
Ask the office to confirm eligibility and coverage before the appointment. Ask what follow-up care would cost if the scan needs another look. If transportation is a problem, say so when you call.
It's never too late to quit
If you still smoke, quitting is worth asking about whether or not you qualify for screening. Your doctor can connect you with counseling and treatments that match your health history. The American Cancer Society's Great American Smokeout takes place on the third Thursday in November, but you don't need to wait for a special day.
If you quit years ago, let that be part of the story, not the end of it. Write down the year you stopped, estimate pack-years, and take the question to your appointment.
What to do next
1. Write down your history. Note your age, years smoked, and average packs per day.
2. Do the math. Multiply packs per day by years smoked to estimate pack-years.
3. Ask your doctor. Say, "Do I qualify for annual lung cancer screening?"
4. Discuss the trade-offs. Ask about benefits, false positives, radiation, and follow-up.
5. Check coverage. Confirm whether insurance or Medicare covers the scan, and talk with your doctor or pharmacist about quitting help if you still smoke.
You don't need to remember every detail before you call. If you've got a rough estimate, your doctor's office can help fill in the rest. What's important is that the question gets asked.
When to call your doctor (or 911)
Screening is for people without symptoms. Don't wait for a screening appointment if you have a cough that doesn't go away, cough up blood, develop chest pain, or lose weight without trying. Call your doctor promptly.
Before the holidays swallow your calendar, jot down roughly how long you smoked and how much. Then call your doctor's office with one question: do I qualify for the yearly scan?
Fact-Checked Medical Sources
Last reviewed: November 2026 · Fact-checked & verified
