In this study we tested, via a randomized control study design, different enrollment options for a scaled city-wide text-based early learning program among 405 mothers who were receiving newborn home visiting services. We found that when automatically enrolled with a voluntary option to opt out, 88.7% of mothers in the experimental group stayed in the program and continued to receive the text-based content over the course of 26 weeks. In contrast, only 1% of mothers in the control group who heard about the text-based program through conventional recruitment flyers voluntarily enrolled in the program. Opt-out and opt-in patterns did not differ by characteristics typically considered as interfering with program participation: low income status, first-time motherhood status, total number of children, maternal language, flagging for depressive symptoms, and household residential instability. Findings suggest that automatic enrollment might be an effective engagement strategy for text- and similar digitally-based early childhood programs.