Objectives <p>Family planning after childbirth can address postpartum individuals’ contraceptive needs and preferences for birth spacing. Our study explored the reasons for not using postpartum contraception and identified opportunities to remove contraceptive barriers.</p> Methods <p>This study used the 2019–2021 Pregnancy Risk Assessment Monitoring System survey of individuals with a recent live birth in 40 states, New York City, and the District of Columbia. We used mixed-methods to analyze categorical and free-text responses on the reasons for not using postpartum contraception. Descriptive and bivariate analysis were applied to characterize the data and explain the relationship between variables. Qualitative data was processed by manual coding procedures.</p> Results <p>Among the 115,917 sample respondents, 22.9% reported not using contraception in the postpartum period. The most common responses were not wanting to use birth control (39.3%) and concerns about contraceptive side effects (32.2%). There were 4,508 postpartum people who completed a free-text response and primarily reported not using contraception due to difficulties with appointment processes and/or not enough time, and infertility or trouble conceiving.</p> Conclusions for Practice <p>We find that postpartum people predominantly reported not wanting to use birth control, contraceptive side effects, infertility, and appointment processes, as reasons for not taking actions to prevent pregnancy. These findings suggest a need for additional counseling about side effects and benefits of contraception and can inform policies and practices that promote reproductive health equity in the postpartum period.</p>