Raised low-density lipoprotein cholesterol (LDL-C) in young adulthood (aged 18-39 years) is associated with atherosclerotic cardiovascular disease (ASCVD) later in life. Most young adults with elevated LDL-C do not currently receive lipid-lowering treatment.This study aimed to estimate the prevalence of elevated LDL-C in ASCVD-free U.S. young adults and the cost-effectiveness of lipid-lowering strategies for raised LDL-C in young adulthood compared with standard care.The prevalence of raised LDL-C was examined in the U.S. National Health and Nutrition Examination Survey. The CVD Policy Model projected lifetime quality-adjusted life years (QALYs), health care costs, and incremental cost-effectiveness ratios (ICERs) for lipid-lowering strategies. Standard care was statin treatment for adults aged ≥40 years based on LDL-C, ASCVD risk, or diabetes plus young adults with LDL-C ≥190 mg/dL. Lipid lowering incremental to standard care with moderate-intensity statins or intensive lifestyle interventions was simulated starting when young adult LDL-C was either ≥160 mg/dL or ≥130 mg/dL.Approximately 27% of ASCVD-free young adults have LDL-C of ≥130 mg/dL, and 9% have LDL-C of ≥160 mg/dL. The model projected that young adult lipid lowering with statins or lifestyle interventions would prevent lifetime ASCVD events and increase QALYs compared with standard care. ICERs were US$31,000/QALY for statins in young adult men with LDL-C of ≥130 mg/dL and US$106,000/QALY for statins in young adult women with LDL-C of ≥130 mg/dL. Intensive lifestyle intervention was more costly and less effective than statin therapy.Statin treatment for LDL-C of ≥130 mg/dL is highly cost-effective in young adult men and intermediately cost-effective in young adult women.