BACKGROUND: The unmet need for family planning (FP) occurs when women want to limit or delay childbearing but lack access to contraception, leading to unintended pregnancies and increased maternal and child mortality, especially in developing countries. This study uses the 2021 PMA-Ethiopia survey to assess unmet need for family planning (FP) among reproductive age women, addressing limitations in previous research that relied on outdated and non-representative data. The findings offer valuable insights to help policymakers address local challenges and improve reproductive health outcomes in Ethiopia. METHODS: This study utilized secondary data from the Performance Monitoring for Action Ethiopia survey conducted in 2021. A total of 5,203 reproductive-aged women were included in this study. STATA version 16 was used to cross-tabulate and fit the models. To account for the hierarchical structure of the data, we employed multilevel logistic regression. We estimated four statistical models: a null model (Model 0) to assess between-community variations, Model I incorporating individual-level predictors, Model II adding community-level factors, and Model III including both. To select the best-fitting model, we conducted model comparison using BIC, AIC, deviance, and log-likelihood ratio (LLR) to assess model performance. We calculated adjusted odds ratios along with their corresponding 95% confidence intervals (CIs). Furthermore, a significance level of p <
0.05 was considered as strong evidence of statistical significance. RESULTS: The prevalence of unmet need for family planning among reproductive-age women was 23.60% [95% CI: 22.46%, 24.78%]. Model comparison indicated that Model III exhibited the best fit, with the lowest AIC (5306) and DIC (5300) values, along with an improved log-likelihood (-2650). Factors positively associated with unmet need included women aged 45-49 [AOR = 4.7, 95% CI: (2.97, 7.43)], 40-44 [AOR = 3.21, 95% CI: (2.23, 4.61)], 35-39 [AOR = 2.47, 95% CI: (1.78, 3.44)], and 30-34 years [AOR = 2.42, 95% CI: (1.76, 3.33)] compared to those aged 15-19 years. Conversely, having 1-2 children [AOR = 0.47, 95% CI: 0.39, 0.56], having 3-4 children [AOR = 0.50, 95% CI: 0.39, 0.63], and having five or more children [AOR = 0.51, 95% CI: 0.39, 0.66] were factors negatively associated with unmet need compared to women who are para 0. Furthermore, the spatial pattern of unmet need for family planning exhibited clustering (Moran's index = 0.25, p-value = 0.0039). The primary cluster is located in the central part of Oromia, northern SNNP, northwest of Sidama, and northeastern part of Southwest Ethiopia. CONCLUSION: This study affirms the ongoing high prevalence of unmet need for family planning in Ethiopia. It identified women's age and parity as crucial factors correlated with unmet need for FP. Additionally, there exists an unequal distribution of the burden of unmet need for FP across the country. To address the varying reproductive health needs at different life stages and parity levels, the interventional plan needs to be based on women's age and the number of children they have. Moreover, location-tailored interventional plans should be employed to optimize family planning related service inequalities.