The Coronary Artery Calcium Scan Works Best For One Specific Group—Here's Why
Coronary artery calcium (CAC) scoring has become one of those tests health-savvy people ask for by name. It's quick, non-invasive, and it hands you a number for something that otherwise feels abstract—how much plaque is already sitting in your arteries. But new research suggests1 the scan is only worth it for a much narrower group of people than the hype implies.
What a calcium score actually measures
When paid for out of pocket, CAC scans cost anywhere from $100 to $400. Most insurance plans, including Medicare, don't reliably cover it because it's classified as screening rather than diagnosis.
The new heart health guidelines narrowed down who should get be getting one of these scans. The 2026 American College of Cardiology and American Heart Association (AHA) Guidelines recommends selective use of calcium scoring for adults whose estimated 10-year risk of heart attack or stroke lands between 3% and just under 10%, according to the AHA'S risk calculator. In other words, people's whose risk is not low enough to ignore, but not high enough to act on decisively.
This change does not come as a surprise to people in the healthcare industry, as cardiology groups have been moving toward targeted calcium scanning3, rather than screening everyone, for years.
What the research says about CAC
Researchers followed just over 6,000 adults ages 45 to 79 with no history of cardiovascular disease. At the start, their average estimated 10-year risk was 6.4%, and 49% already had some detectable calcium. Over 10 years, 6% of people (366 individuals) had a heart attack, stroke, or related event.
Adding a calcium score to the risk equations sharpened predictions only slightly across the full group, and for some risk categories it didn't change the estimate at all. That's a useful reality check for anyone hoping one scan will settle the question, and part of why researchers keep hunting for better ways to spot heart risk early.
Where the scan changed the picture
The CAC scan was most impactful for people whose estimated risk sat in the borderline range of 3% to just under 5%. Calcium scores clearly separated who went on to have an event and who didn't in this group. Here's how scores mapped on to risk for these people:
- Score of 0: 1.9% had an event over 10 years
- Above 0 but under 100: 3.9%
- 100 to under 300: 7.4%
- 300 or higher: 14.3%
That's about seven times the difference in risk between people who looked pretty much the same on paper. This means a calcium score can change how urgently someone in that gray zone handles their heart risk with their doctor.
Should you ask your doctor for a CAC scan?
If your risk falls below 3% or comfortably above 10%, the scan is unlikely to shift your plan. Low risk tends to stay low regardless of what the images show, and high risk usually gives you and your doctor enough to act on already.
If your risk falls in the intermediate range—above 5%, but below 10%—the guideline still recommends considering a scans, but it likely won't change much. When you're in the intermediate range, prevention is already on the table, so a calcium score is less likely to be the thing that alters your plan. High CAC scores led to larger shifts in prevention and risk assessment for people on the borderline end.
And remember, risk isn't fixed. Midlife hormonal changes can move it, which is a reason to revisit your numbers rather than treat one scan as the final word.
CAC also isn't the only test worth considering. Lp(a) is another predictive blood test to ask about, some cardiac specialists point to fasting insulin as an overlooked marker, and standard heart health labs still do a lot of the work. If you're not sure where to start, asking your doctor about bloodwork worth prioritizing after 40 is a great first step.
The takeaway
If you have been thinking about getting a CAC scan, ask your doctor about your 10-year risk at your next appointment. That number decides whether a calcium scan will tell you anything new or just cost you a few hundred dollars to confirm what you already know.
If your risk shows the scan isn't worth your time, put that energy toward the habits that lower risk in every category—strength training, sleep, nutrition, and connection.