Assessment of the National Science Foundation's 2015 Geospace Portfolio Review provides an independent assessment of the ICCGS report. This publication assesses how well the ICCGS provides a clear set of findings, conclusions, and recommendations for Geospace Section that align with the science priorities of the NRC decadal survey, and adequately take into account issues such as the current budget outlook and the science needs of the community. Additionally, this study makes recommendations focused on options and considerations for NSF's implementation of the ICCGS recommendations.