Background: The use of coronary artery calcium scoring (CAC) to guide primary prevention statin therapy in those with a family history of premature coronary artery disease (FHCAD) is inconsistently recommended in guidelines, and usually not reimbursed by insurance. We assessed the cost-effectiveness of CAC compared with traditional risk factor–based prediction alone in those with an FHCAD. Methods: A microsimulation model was constructed in TreeAge Healthcare Pro using data from 1,083 participants in the CAUGHT-CAD (Coronary Artery Calcium Score: Use to Guide Management of HerediTary Coronary Artery Disease) trial. Outcomes assessed were quality-adjusted life years (QALYs): cost-effectiveness was assessed over a 15-year time horizon from the perspective of the US health care sector using real-world statin prescribing, accounting for the effect of knowledge of subclinical disease on adherence to guideline-directed therapies. Costs were assessed in 2020 USD, with discounting undertaken at 3%. Results: Statins were indicated in 45% of the cohort using the CAC strategy and 27% using American College of Cardiology/American Heart Association (2019) treatment strategies. Compared with applying a statin treatment threshold of 7.5%, the CAC strategy was more costly ($145) and more effective (0.0097 QALY) with an incremental cost-effective ratio (ICER) of $15,014/QALY. CAC ICER was driven by CAC acquisition and statin prescription cost and improved with certain patient subgroups: male, age >60 years, and 10-year risk pooled cohort equation risk ≥7.5%. CAC scanning of low-risk patients (10-year risk <5%) or those 40 to 50 years of age was not cost-effective. Conclusion: Systematic CAC screening and treatment of those with FHCAD and subclinical disease was more cost-effective than management using statin treatment thresholds, in the US health care system.