In 2018, cardiovascular society cholesterol guidelines recommended the use of coronary artery calcium to guide statin therapy in patients 40-79 years of age who are at intermediate risk by multiple risk factor equations (ie, estimated 10-year risk for atherosclerotic disease of 7.5%-19.9% but in whom statin benefit is uncertain). Many such patients have no coronary calcium and remain at <5% risk over the next decade; hence, statin therapy can be delayed until a repeat calcium scan is conducted. Exceptions include patients with severe hypercholesterolemia, diabetes, and a strong family history of atherosclerotic disease. If coronary calcium equals 1-99 Agatston units, the 10-year risk is borderline (5% to <7.5%) and statin therapy is optional pending a repeat scan. If coronary calcium equals 100-299 Agatston units, the patient is clearly statin eligible (7.5% to <20% 10-year risk). And finally, if coronary calcium is ≥300 Agatston units, a patient is at high risk and is a candidate for high-intensity statins. Risk factor analysis combined judiciously with coronary calcium scanning offers the strongest evidence-based approach to use of statins in primary prevention.