This paper presents a new approach to assess the e-Government maturity with an aim to facilitate public sector innovation in developing countries. NIAT takes a rare approach to comprehensively assess the needs and capabilities by a participatory measure. It provides a standardized assessment process in order to ensure the quality of data. NIAT contributes to the service innovation by providing improved contents for e-Government services and identifying priorities of ICT strategy. It also stimulates organizational innovation in the public sector by building capacity of stakeholders across governmental silos and sectors. NIAT is a toolkit for quick deployment of ICT strategy and action plan grounded on actual experiences of e-Government developments in Korea. By offering a proven, pre-costed pool of projects readily applicable in practice, NIAT allows an accelerated prioritization of the relevant projects. In addition, the participatory process involving key actors in the government is a consensus building mechanism to generate political buy-ins for the project chosen.