In this opinion, the GMO Panelassessed the five-event stack maize MON87427xMON89034x1507xMON88017x59122 and its 25 subcombinations, independently of their origin. The GMO Panelhas previously assessed the five single events combined to produce this five-event stack maize and 11 subcombinations of these events and did not identify safety concerns. No new data on the single events or their previously assessed subcombinations, leading to modification of the original conclusions were identified. The combination of the single events and of the newly expressed proteins in the five-event stack maize did not give rise to issues - based on the molecular, agronomic/phenotypic or compositional characteristics - regarding food and feed safety and nutrition. Considering the scope of this application, the known biological function of the newly expressed proteins and the data available for the five-event stack maize and its previously assessed maize subcombinations, the GMO Panelconsidered that different combinations of the single events would not raise environmental concerns. The GMO Panelconcludes that the five-event stack maize is as safe and as nutritious as the non-genetically modified (GM) comparator and the tested non-GM reference varieties in the context of its scope. For the 14 maize subcombinations for which no experimental data were provided, the GMOPanelassessed the likelihood of interactions among the single events, and concluded that theircombinations would not raise safety concerns. These maize subcombinations are therefore expected to be as safe as the single events, the previously assessed subcombinations and maize MON87427xMON89034x1507xMON88017x59122. Since the post-market environmental monitoring plan for the five-event stack maize does not include any provisions for the 14 maize subcombinations not previously assessed, the GMO Panelrecommended the applicant to revise the plan accordingly.