Background: Favorable attitudes toward modern family planning methods (MFPMs) among Jordanian and Syrian women do not always translate into behavioral changes, and the availability and cost of MFPMs do not appear to be related to either prior stalls in fertility rates in Jordan or to the current and likely temporary decline in fertility rates. This study aimed to determine whether behavioral economics (BE)-based family planning interventions influence the use of any family planning method, MFPMs use, continuation of MFPMs use, and pregnancy rates among women in Jordan. The BE-based family planning interventions included personalized text messaging and augmented counseling based on framing and identity-priming BE principles, with their effects tested over a 9-month period in the postpartum period following the birth of a child. Methods: A parallel-group cluster randomized controlled trial was conducted to compare two interventions, augmented counseling based on framing and identity-priming BE principles and personalized mobile phone text messages reminders, aiming to improve the utilization of MFPMs among postpartum women over status quo family planning services in comprehensive health centers in the north of Jordan. Results: In total, 1032 participated in the study: 295 women in the control group; 326 women in Intervention Group 1, which received only augmented counseling; and 411 women in intervention Group 2, which received augmented counseling and monthly text messages. The rates of using MFPMs in the counseling group and the counseling and messages group 3 months (54.7% and 57.1%, respectively), 6 months (50.0% and 51.7%, respectively), and 9 months (49.5% and 52.0%, respectively) were significantly higher than the rates among women in the control group (40.6% at 3 months, 37.6% at 6 months, and 34.3% at 9 months). Overall, 26.8% of women in the control group, 42.1% of women in the counseling-only group, and 45.2% of women in the counseling and messages group used MFPMs continuously for all 9 months. At 9 months, the pregnancy rate was significantly much higher in the control group (13.7%) compared to women in the counseling-only group (7.0%) and to women in the counseling and messages group (7.4%). Conclusions: Simple BE-based interventions can be effective methods for enhancing the use of MFPMs and maintaining the anticipated decline in Jordan’s total fertility rate.