Adults aged 50 to 80 who have smoked the equivalent of 20 pack-years and who still smoke or quit within the past 15 years are advised to get a lung cancer screening scan every year, according to the Centers for Disease Control and Prevention (CDC). This guide explains how that threshold is calculated, what the scan involves, what the risks are and where Maryland residents can find free help to quit smoking.
Who should be screened for lung cancer?
The CDC’s lung cancer screening page, dated May 12, 2026, says the U.S. Preventive Services Task Force (USPSTF) recommends yearly screening for adults who meet all three of these criteria:
- They have a smoking history of at least 20 pack-years.
- They smoke now or have quit within the past 15 years.
- They are between 50 and 80 years old.
The test is a low-dose computed tomography scan, usually shortened to LDCT. The CDC describes it as a quick, painless scan that uses a small amount of radiation. The agency says screening can reduce deaths by finding lung cancer early, when treatment works best.
| Quick facts | Detail |
|---|---|
| Recommended ages | 50 to 80 |
| Smoking history | At least 20 pack-years |
| Quit window | Currently smoke, or quit within the past 15 years |
| Test | Low-dose CT (LDCT), every year |
| Source | CDC, page dated May 12, 2026 |
What is a pack-year, and how is it counted?
The CDC defines a pack-year as smoking an average of one pack of cigarettes per day for one year. Its own examples show two routes to 20 pack-years: a pack a day for 20 years, or two packs a day for 10 years.
Illustrative arithmetic shows how the number works. Pack-years equal packs per day multiplied by years of smoking:
| Illustrative smoking history | Calculation | Pack-years |
|---|---|---|
| 1 pack a day for 20 years | 1 × 20 | 20 |
| 2 packs a day for 10 years | 2 × 10 | 20 |
| 1.5 packs a day for 20 years | 1.5 × 20 | 30 |
| Half a pack a day for 30 years | 0.5 × 30 | 15 |
In this illustration, the first three histories reach the 20 pack-year threshold on that measure, and the last does not. Age and the quit window still have to be met as well. Whether a particular person qualifies is a question for a doctor, who can go through the full history.
When should screening stop?
The CDC says the Task Force advises stopping yearly screening when a person:
- Turns 81 years old.
- Has not smoked in 15 or more years.
- Develops a health problem that makes them unwilling or unable to have surgery if lung cancer is found.
The reasoning is practical. The point of screening is to find a cancer early enough to treat it, so the test makes less sense for someone who could not or would not undergo treatment.
What are the risks of a screening scan?
Screening is not risk-free, and the CDC lists three downsides to weigh:
- False-positive results, which can lead to unneeded follow-up tests and surgeries.
- Overdiagnosis, which can lead to treatment that was not needed.
- Radiation-related cancer from repeated scans.
For that reason the CDC advises people to talk with their doctor about their risk of lung cancer and the possible risks of screening. If screening is appropriate, the page says, a doctor can refer a patient to a high-quality screening facility. The same balancing of benefit and harm applies to other cancer tests, as the Herald’s guide to mammogram screening explains.
Will insurance or Medicare pay for the scan?
According to the CDC, most insurance plans and Medicare help pay for recommended lung cancer screening. It adds that follow-up tests after an abnormal result may involve costs such as co-pays or deductibles, and it advises checking with a plan about covered benefits. Medicare can be reached at 1-800-MEDICARE (1-800-633-4227).
What symptoms should not wait for a screening appointment?
Screening is meant for people without symptoms. The CDC’s symptoms page, dated May 12, 2026, lists these common signs of lung cancer:
- A cough that is getting worse or lasting a long time
- Chest discomfort or pain
- Difficulty breathing
- A whistling sound when breathing
- Blood in the cough
- Constant exhaustion
- Unexplained weight loss
The page also lists repeated pneumonia and enlarged lymph nodes in the chest as possible signs. It notes that most people with lung cancer have no symptoms until the disease is advanced, and that these signs can come from other illnesses. Its advice is to talk to a doctor to find the cause. Anyone with severe trouble breathing or chest pain should call 911.
What raises the risk beyond smoking?
Cigarette smoking is the “number one risk factor for lung cancer,” according to the CDC’s risk-factor page, dated May 18, 2026. The page links smoking to about 80% of U.S. lung cancer deaths and says smokers are 15 to 30 times more likely to get or die from lung cancer than nonsmokers. It also says tobacco smoke contains more than 7,000 chemicals, at least 70 of which cause cancer, and that cigars and pipes raise risk as well.
Other factors on the CDC list include:
- Secondhand smoke
- Radon, a naturally occurring gas that can build up in buildings
- Workplace exposure to asbestos, arsenic, diesel exhaust, some forms of silica and chromium
- Air pollution
- Arsenic and radon in well water, mainly from private wells
- A personal or family history of lung cancer
- HIV infection
- Radiation therapy to the chest
- Beta carotene supplements, especially in people who smoke at least a pack a day
Why does radon matter for a home in Maryland?
The CDC’s radon page, dated June 18, 2026, describes radon as an odorless, invisible radioactive gas that comes naturally from rocks, soil and water and can collect in the air inside homes. It says there is no known safe level of radon, and that radon is the second leading cause of lung cancer deaths in the United States after cigarette smoke. The Environmental Protection Agency (EPA) and the Surgeon General’s office estimate that it causes more than 21,000 lung cancer deaths each year, the CDC reports.
The CDC says testing is the only way to know a home’s level. Test kits are sold at hardware stores and online, or a state radon office can advise. The EPA recommends fixing a home when radon is at or above 4 picocuries per liter (pCi/L), and the CDC advises reducing it even below that level. Anyone who makes repairs should retest afterward to confirm they worked. The CDC does not give a Maryland-specific radon figure on that page, so Maryland homeowners should look to the Maryland Department of Health or a test kit for local guidance.
Where can Marylanders get free help to quit?
Quitting is the most direct step for current smokers, and the state offers support. According to the Maryland Department of Health, the Maryland Tobacco Quitline at 1-800-QUIT-NOW (1-800-784-8669) is free and confidential and available 24 hours a day, seven days a week. The department’s page describes it as open to Maryland residents over age 13 who want to quit any form of tobacco.
| Quitline feature | What the state describes |
|---|---|
| Phone | 1-800-QUIT-NOW (1-800-784-8669) |
| Text | Text READY to 34191 |
| Online | quitnow.net/maryland |
| Counseling | Quit coaches help build a plan and manage cravings |
| Nicotine replacement | Free patches or gum while supplies last |
| Teens | Ages 13 to 17 can also join Live Vape Free by texting VAPEFREE to 873-373 |
The page, which carries no date, also says intensive multi-call programs exist for youth ages 13 to 17 and pregnant women, and that nonsmokers can enroll to help a family member or friend. It reports that 3 in 5 callers smoked fewer cigarettes by the end of the program, based on more than 2,500 recent participants. Because the page is undated, readers should confirm current eligibility and supplies when they call.
Giving up tobacco is hard, and many people feel stress or low mood along the way. Anyone in emotional crisis can call or text 988, as described in the Herald’s guide to the 988 Suicide and Crisis Lifeline in Maryland. Smoking also raises other cardiovascular risks, which the Herald covers in its look at high blood pressure and the CDC numbers.
Starting the conversation with a clinician
The CDC’s eligibility rules are narrow by design: an age range, a smoking history, a quit window and a general fitness for treatment. Anyone who thinks they might fit should write down roughly how many packs they smoked per day and for how many years, then ask a doctor whether a yearly scan makes sense. Those who do not qualify, including people who never smoked, can still lower their risk by testing their home for radon, avoiding secondhand smoke and reporting new, lasting symptoms promptly.
This article is general information, not medical advice. Talk with a health care professional about your own screening needs and any symptoms.
Sources: Centers for Disease Control and Prevention; Maryland Department of Health
