What does a calcium score of zero mean?

After a coronary artery calcium (CAC) test, a CAC score of 0 is the best possible result you could get.

When it comes to a calcium score, the lower your number, the better. A calcium score of zero means no calcified plaque was found in your heart arteries, and it's one of the most reassuring results you can get from this test.

But this doesn’t guarantee that your heart is completely safe. Your calcium score only sees one kind of plaque, and your CAC score can increase over time.

Below, you'll learn how reassuring a zero score is, how common it is, and the situations where a CT angiogram (CCTA) may be worth considering.

Key takeaways

A calcium score of zero means no calcified plaque was detected. This is generally a reassuring result.
A score of zero does not rule out soft plaque or reduce your cardiovascular risk to zero. A calcium score cannot detect soft, noncalcified plaque.
Your symptoms and other risk factors still matter. Whether you need a CT angiogram, repeat calcium scoring, or another next step should be decided individually with your doctor.

What a calcium score of zero actually means

A coronary calcium score of 0 means your scan did not find any hard (calcified) plaque in your coronary arteries.

This is good news. A result of zero is the best possible outcome this test can give. However, a zero score doesn’t guarantee your arteries are clean.

A calcium scan does not show soft plaque, which is plaque that has not calcified. A calcium score measures only calcified plaque.

A zero score usually means one of two things:

Your arteries have little to no plaque, which is the ideal scenario.
You have soft plaque that hasn't calcified yet.

Either is possible. A CT angiogram uses contrast dye to show soft and calcified plaque, as well as narrowing in your coronary arteries. Whether it is appropriate depends on your symptoms and overall risk.

Is a calcium score of zero good?

Yes. A calcium score of zero is the best result you could get.

Research from the Multi-Ethnic Study of Atherosclerosis (MESA) found that a calcium score of zero was the single strongest marker among more than a dozen tools compared, ahead of markers like family history, inflammation levels, and metabolic syndrome status.

Experts sometimes call this the “power of zero,” because a single result can meaningfully lower a person's estimated risk and, for some, help determine whether starting a medication like a statin makes sense.

Still, a zero score can be overconfident because it can miss soft plaque. This is partly why age and other risk factors change how much reassurance a zero score should actually give you.

Does a calcium score of zero stay zero? The "warranty period"

A score of zero today doesn’t mean it will stay zero forever. Calcified plaque can develop over time as people age and their risk factors change.

Researchers describe the time during which a zero score remains reassuring as a “warranty period.” For selected adults, the 2026 ACC/AHA multisociety guideline says repeating CAC testing in 3 to 7 years may be reasonable, depending on overall risk and whether the result would change treatment.

This is part of why doctors sometimes recommend a repeat scan a few years down the line, especially if your risk factors have changed, rather than treating a single zero result as settled permanently.

How common is a zero calcium score?

Zero is more common than many people expect, especially at younger ages and in women.

According to cardiovascular research published in the American Heart Association journal Circulation, 83 to 95 percent of women under 50 have a calcium score of zero. Even in middle age, only about a third of women show any detectable calcium.

Men tend to develop detectable coronary calcium earlier than women, so a zero score becomes less common at a younger age in men.

The limitation: what a zero score can't see

A calcium score test detects only calcified plaque. It cannot show noncalcified plaque or tell whether a coronary artery is narrowed.

So, while a zero means you have no calcified plaque, you may still have soft plaque build-up.

A score of zero is associated with low cardiovascular risk, but it does not reduce risk to zero. Cardiovascular events can still occur, especially when other risk factors are present.

Age affects how well a zero score rules out obstructive coronary disease. In a large study of people evaluated for symptoms, 93 percent of those under 40 had a zero score, compared with 51 percent of those over 40.

Among participants who had obstructive coronary disease, 58 percent of those under 40 still had a zero score, compared with 14 percent of those over 40 and 5 percent of those over 70. These findings apply to a symptomatic population and should not be generalized to everyone who gets a screening calcium scan.

In other words, a zero score is less able to rule out obstructive disease in younger people, particularly those with symptoms.

So how do you look for soft plaque? A CT angiogram can detect both soft and hard plaque and show where plaque has built up. Whether it makes sense depends on your symptoms and overall risk.

When additional evaluation may still make sense

Remember, a zero score doesn't erase your other risk factors, nor does it mean you should ignore any worrying symptoms.

Even after a score of zero, you may need additional testing if you:

Have a strong family history of early heart disease
Have other risk factors — for example, if you have diabetes or high blood pressure
Experience symptoms like chest pain or shortness of breath

Additional testing may be worth discussing with your doctor, even with a reassuring scan in hand.

The right evaluation depends on why you are being assessed. It may include:

A follow-up calcium score test within a few months or years
A more advanced scan, like a CT angiogram
Comprehensive blood tests, including genetic cholesterol marker Lp(a)

Checking Lp(a) with a zero calcium score

The 2026 American Heart Association guideline recommends that all adults have lipoprotein(a), or Lp(a), measured at least once, even if they have a zero calcium score.

Think of Lp(a) as a cousin of LDL cholesterol. It is mostly inherited, and high Lp(a) independently raises cardiovascular risk even when LDL cholesterol is low. A calcium score does not measure it.

If your Lp(a) is high, your doctor may focus on lowering LDL cholesterol and managing other risk factors. Whether you need additional imaging depends on your symptoms and overall risk.

What should you do with a zero score?

A zero score is genuinely good news, and it's worth treating it that way.

That said, a few things are worth doing next, regardless of how reassuring your result feels:

Keep up your healthy habits. A zero score reflects that your arteries have no detectable calcium today, but it’s not a lifetime guarantee. A healthy diet, regular exercise, and other healthy habits can help protect your heart.
Know your other numbers. Cholesterol, blood pressure, blood sugar, and Lp(a) still matter. Unlike the others, Lp(a) generally needs to be measured only once because it is mostly inherited.
Don't brush off symptoms. Chest pain, shortness of breath, or unusual fatigue deserve attention regardless of what your last scan showed.
Ask your doctor about retesting. Discuss whether and when another calcium scan would change your care.

None of this is meant to undercut the good news. A zero score is one of the best results you can get. But for your long and healthy life, it’s worth taking action to protect your heart health.

The bottom line on a calcium score of zero

A calcium score of zero is a genuinely reassuring result and one of the strongest low-risk signals available from a single scan.

But it isn't an absolute guarantee. A calcium score does not detect noncalcified plaque, so your cardiovascular risk is low, not zero.

If you have other risk factors, such as diabetes or high Lp(a), discuss with your clinician whether additional evaluation would change your care.

Confidence in your heart health

A calcium score of zero only rules out calcified plaque. Our CT angiogram can detect soft plaque too, but it is not necessary for everyone. Whether it is appropriate depends on your symptoms and overall risk.

Reserve your spot