Improved strategies and scalable interventions to engage low-socioeconomic status (SES) smokers in tobacco treatment are needed. We tested an intervention designed to connect low-SES smokers to treatment services, implemented through Minnesota's National Breast and Cervical Cancer Early Detection Program (Sage) in 2017; the trial was designed to last 3 months (July through October). Participants were female smokers who were 250% below the federal poverty level (randomized N = 3723; analyzed N = 3365). Using a factorial design, participants were randomized to six intervention groups consisting of a proactive call (no call vs call) and/or a financial incentive offered for being connected to treatment services ($0 vs $10 vs $20). Simple randomization was conducted using Stata v.13. All individuals received direct mail. Participants and staff were blinded to allocation. The outcome was connection via phone to QUITPLAN Services®, Minnesota's population-based cessation services. Groups that received $10 or $20 incentives had higher odds of treatment engagement compared to the no incentive group [respectively, OR = 1.94; 95% CI (1.19-3.14); OR = 2.18; 95% CI (1.36-3.51)]. Individuals that received proactive calls had higher odds of treatment engagement compared to individuals not called [OR = 1.59; 95% CI (1.11-2.29)]. Economic evaluation revealed that the $10 incentive, no call group had the best cost-benefit ratio compared to the no incentive, no call group. Direct mail with moderate incentives or proactive calling can successfully encourage connections to population-based tobacco treatment services among low-SES smokers. The intervention could be disseminated to similar programs serving low-SES populations. This trial is registered at ClinicalTrials.gov (NCT03760107).