This document discusses the implementation of portfolio management at the Department of Energy (DOE) and National Nuclear Security Administration (NNSA) to improve budget transparency and justification. It describes how the Planning, Programming, Budgeting, and Evaluation (PPBE) process was strengthened by developing a work breakdown structure and implementing a portfolio management system called the Objective Portfolio Planning and Management (OPPM) tool. The OPPM tool collects project data, allows for analysis of costs, dependencies and risks, and supports management reviews to provide full visibility and justification of budget requests. This enhanced transparency addresses prior Government Accountability Office findings about unknown total facility costs and unidentified stockpile services costs.