This economic evaluation using a decision-analytic Markov model with a simulated cohort of women aged 30 years found that undergoing both risk-reducing mastectomy (RRM) and risk-reducing salpingo-oophorectomy (RRSO) was most cost-effective, maximizing cancers prevented for individuals carrying BRCA1 (RRM at age 30 years; RRSO at age 35 years), BRCA2 (RRM at age 35 years; RRSO at age 40 years), and PALB2 (RRM at age 40 years; RRSO at age 45 years) pathogenic variants, while RRSO was cost-effective at age 45 years for women with RAD51C, RAD51D, and BRIP1 pathogenic variants. The gene discussed is RAD51D; the disease is cancer.