Higgins and colleagues' recently-completed randomized controlled trial and pooled data with 4 related trials of smoking cessation in pregnant women in Vermont (USA) showed that abstinence-contingent financial incentives (FI) increased abstinence over control conditions from early pregnancy through 24-weeks postpartum. Control conditions were best practices (BP) alone in the recent trial and payments provided independent of smoking status (noncontingently) in the others. This paper reports economic analyses of abstinence-contingent FI. Merging trial results with maternal and infant healthcare costs from all Vermont Medicaid deliveries in 2019, we computed incremental cost-effectiveness ratios (ICERs) for quality-adjusted life years (QALYs) and compared them to established thresholds. The healthcare sector cost (±standard error) of adding FI to BP averaged $634.76 ± $531.61 per participant. Based on this trial, the increased probability per BP + FI participant of smoking abstinence at 24-weeks postpartum was 3.17%, the cost per additional abstinent woman was $20,043, the incremental health gain was 0.0270 ± 0.0412 QALYs, the ICER was $23,511/QALY gained, and the probabilities that BP + FI was very cost-effective (ICER≤$65,910) and cost-effective (ICER≤$100,000) were 67.9% and 71.0%, respectively. Based on the pooled trials, the corresponding values were even more favorable-8.89%, $7138, 0.0758 ± 0.0178 QALYs, $8371/QALY, 98.6% and 99.3%, respectively. Each dollar invested in abstinence-contingent FI over control smoking-cessation programs yielded $4.20 in economic benefits in the recent trial and $11.90 in the pooled trials (very favorable benefit-cost ratios). Medicaid and commercial insurers may wish to consider covering financial incentives for smoking abstinence as a cost-effective service for pregnant beneficiaries who smoke. Trial Registration: ClinicalTrials.gov identifier: NCT02210832.