This budget impact analysis estimates the costs of treating heterozygous familial hypercholesterolemia (HeFH) patients with alirocumab over one year within a hypothetical commercial health plan. The analysis found that treating an estimated 1,120 HeFH patients with alirocumab would result in a total drug cost of $11.7 million for the health plan, or $0.976 per member per month. Sensitivity analysis showed that the model was most sensitive to changes in the wholesale acquisition cost of alirocumab. While alirocumab is more effective than other options, its high cost needs to be weighed against potential long-term outcomes benefits for formulary decision making.