Transmutation of minor actinides (MA) remains one of the key goals towards a sustainable waste management strategy [1]. Transuranic elements such as plutonium, neptunium, americium, and curium, are the primary contributors to long-term radiotoxicitiy and heat generation in spent fuel, despite their relatively small mass percentage. Incorporation of MA in fuels during fabrication for subsequent recycling in the liquid metal fast breeding reactor (LMFBR) is one of the routes that has been pursued in many countries. The addition of MA to the fuel matrix poses scientific issues and associated challenges. For example, it is expected that the additional He from decay of the MA can contribute to the fuel pin over-pressurization. For oxide fuels, the addition of Am and Np in the MOX matrix (which are called MA-MOX) has impact on the oxygen-to-metal ratio (O/M), which governs diffusion and thermal properties. Moreover, the O/M is crucial in determining cladding corrosion. Finally, due to a different fission split among the various actinides, the isotopic and chemical distribution of fission products also shifts relative to that of standard MOX fuel [2]. Irradiation tests have been performed worldwide to address these issues. Initial tests in the Japanese JOYO reactor were focused on the understanding of Am and Np redistribution during the first hours of irradiation in order to dismiss the penalty in thermal conductivity and melting point due to addition of the minor actinides as a safety concern [3]. The SUPERFACT program conducted tests to medium burnup (i.e., between 4.5 and 6.5 % FIMA), showing that the performance was satisfactory and Post-Irradiation Examination (PIE) results were similar to what obtained for standard MOX pins [4,5]. Extension to high burnup above 10% FIMA has been hindered by the early shut down of sodium-cooled fast reactors, and no data are currently available in the open literature so far. The Advanced Fuel Campaign of the Department of Energy has been pursuing irradiation to high burnup of MA-MOX (initial composition: (U0.75Pu0.20Np0.03Am0.02)O1.98 fuel with HT-9 cladding) to fill this gap. Initial PIE results on a high burnup MA-MOX have been obtained at Idaho National Laboratory on a specimen with 10.6% FIMA, showing that the rod did not fail [6]. However, no information about the minor actinide redistribution was obtained, which is one of the parameters of merit with utmost importance to assess the performance of this type of fuels. In parallel, quantification of fission product deposits and their radial distribution will be gathered to compare it with the data available in literature on conventional MOX. The present investigation will provide unique detailed insight on the chemical composition and MA redistribution to complete the characterization of MA-MOX at high burnup.