Short answer
A coronary calcium score measures calcified plaque in your heart arteries on a low-dose CT scan. A score of 0 means no calcium was seen and a low near-term risk of heart attack; anything above 0 means plaque, graded from minimal to extreme. US guidelines use it selectively, in adults at borderline or intermediate risk, to help decide on cholesterol treatment.
What the scan and the score are
You lie on a CT table with small electrodes on your chest and hold your breath for short periods. MedlinePlus says the whole heart scan takes about 10 minutes.
The score, in Agatston units, is based on how much calcium is found in your heart arteries. MedlinePlus calls 0 normal, meaning the chance of a heart attack over the next several years is very low. Above 0, it grades plaque as minimal (1 to 9), mild (10 to 99), moderate (100 to 299), severe (300 to 999) or extreme (1,000 or more).
How guidelines use it
The 2026 ACC/AHA dyslipidemia guideline replaced the 2018 version in March 2026. It recommends a calcium scan for men 40 and older and women 45 and older at intermediate risk, and some at borderline risk, when the choice about cholesterol-lowering treatment is still unclear. Risk is now estimated with the PREVENT calculator. The 2018 guideline had called the scan only a reasonable option.
Any calcium above 0 now supports starting treatment. At 1 to 99, and below the 75th percentile for your age, sex and race, a statin is reasonable with an LDL goal under 100 mg/dL. At 100 to 299, or at the 75th percentile or higher, the LDL goal is under 70 mg/dL. At 300 to 999 it is under 70, with under 55 reasonable. At 1,000 or more it is under 55 mg/dL.
A score of 0 lets you and your clinician put off treatment and focus on lifestyle, if you prefer that and none of these apply: familial hypercholesterolemia or LDL above 190 mg/dL, diabetes after age 40, current smoking, or a strong family history of early heart disease. The guideline then suggests a repeat scan in 3 to 7 years.
Radiation and price
In 3,442 participants of the MESA study scanned on modern machines, the average effective dose was 1.05 mSv, ranging from 0.53 to 1.26 mSv by scanner. The FDA's CT page, dated 2017, lists a typical 3 mSv for this scan and 16 mSv for a coronary CT angiogram.
Some health systems publish cash prices. Memorial Healthcare System in Broward County, Florida, and Valley Health each list a $99 self-pay rate. Both require a prescription.
Who it is not for
The scan helps when the treatment decision is uncertain. The 2026 guideline recommends a statin without a scan for people with existing cardiovascular disease and for LDL of 190 mg/dL or more. It also recommends cholesterol-lowering treatment for adults 40 to 75 with diabetes, chronic kidney disease stage 3 or 4, or HIV, whatever their LDL.
After age 75, the guideline says a scan may be reasonable for some people who are unsure about treatment, because little or no calcium can support skipping it. Talk to your doctor about whether a scan would change your plan.
Related questions
Is a calcium score of 0 good?
Yes. MedlinePlus says a score of 0 means the chance of a heart attack over the next several years is very low. Under the 2026 guideline, smokers, people over 40 with diabetes, those with a strong family history of early heart disease, and those with familial hypercholesterolemia or LDL above 190 mg/dL are exceptions to putting off treatment.
Do I need a referral for a calcium score?
Often yes. Both health systems we found with published $99 self-pay prices require a prescription.
How often should you repeat it?
After a score of 0 at intermediate or borderline risk, the 2026 guideline suggests a repeat scan in 3 to 7 years if treatment is put off. That timing is new in 2026.
Read next
Sources
- MedlinePlus (National Library of Medicine): Heart CT scan (reviewed 2025)
- American Heart Association: Top Things to Know, 2026 Guideline on the Management of Dyslipidemia
- ACC: ACC, AHA release new clinical guideline for managing dyslipidemia (13 Mar 2026)
- Blumenthal et al., 2026 ACC/AHA multisociety Guideline on the Management of Dyslipidemia (PubMed record)
- Messenger et al., Int J Cardiovasc Imaging: Coronary calcium scans and radiation exposure in MESA (2016)
Published 2026-10-07 · Last checked 2026-10-07
Educational content, not medical advice. Made for the United States.