Sudden Unexpected Infant Death (SUID) remains the leading cause of death among U.S. infants age 1–12 months. Extensive epidemiological evidence documents maternal prenatal cigarette smoking as a major risk factor for SUID, but leaves unclear whether quitting reduces risk. This Commentary draws attention to a report by Anderson et al. (Pediatrics. 2019, 143[4]) that represents a breakthrough on this question and uses their data on SUID risk reduction to delineate potential economic benefits. Using a five-year (2007–11) U.S. CDC Birth Cohort Linked Birth/Infant Death dataset, Anderson et al. demonstrated that compared to those who continued smoking, women who quit or reduced smoking by third trimester decreased the adjusted odds of SUID risk by 23% (95% CI, 13%–33%) and 12% (95% CI, 2%–21%), respectively. We applied these reductions to the U.S. Department of Health and Human Services' recommended value of a statistical life in 2020 ($10.1 million). Compared to continued smoking during pregnancy, the economic benefits per woman of quitting or reducing smoking are $4700 (95% CI $2700–$6800) and $2500 (95% CI, $400–$4300), respectively. While the U.S. obtained aggregate annual economic benefits of $0.58 (95% CI, 0.35–0.82) billion from pregnant women who quit or reduced smoking, it missed an additional $1.16 (95%CI 0.71–1.60) billion from the women who continued smoking. Delineating the health and economic impacts of decreasing smoking during pregnancy using large epidemiological studies like Anderson et al. is critically important for conducting meaningful economic analyses of the benefits-costs of developing more effective interventions for decreasing smoking during pregnancy.