This study evaluates whether Papua's Special Autonomy Fund is associated with poverty reduction and whether regional gross domestic product (GRDP) and income inequality moderate that relationship in the Mamta Customary Area. An explanatory sequential mixed-methods design was used. The quantitative phase analyzes a balanced census panel covering all five Mamta regencies/cities—Jayapura Regency, Keerom, Sarmi, Mamberamo Raya, and Jayapura City—during 2016–2024, yielding 45 region-year observations from the Directorate General of Fiscal Balance (DJPK) and Statistics Indonesia (BPS). Because the data cover the complete set of Mamta jurisdictions rather than a probability sample, the number of observations is fixed by the study scope and period; interaction estimates are therefore interpreted cautiously. Poverty, GRDP, and the Gini Ratio are official macro-level indicators, so psychometric reliability coefficients are not applicable; data quality was addressed through source verification and cross-year consistency checks. Fixed-effects panel regression with moderated interactions was followed by qualitative content analysis of peer-reviewed studies, government and audit documents, and policy sources using repeated reading, coding, category development, thematic synthesis, and source triangulation. The two phases were integrated during interpretation. The Special Autonomy Fund is positively associated with poverty (β = 0.0289, p = .0265), GRDP is negatively associated with poverty (β = -0.00021, p = .0454), and the Gini Ratio is positively associated with poverty (β = 8.0866, p = .0339). The interaction terms are only marginally significant at the 10% level (p = .0532 and p = .0569). These associations do not establish causality. Qualitative evidence identifies four recurring explanatory themes: budget-priority mismatch, weak governance and supervision, spatial-economic inequality, and socio-cultural misalignment. The findings suggest that larger fiscal transfers alone are insufficient without stronger targeting, accountability, inclusive growth, and meaningful indigenous participation.