Since the passage of the Every Student Succeeds Act (ESSA) in December 2015, state education agencies (SEAs) have invested much time, effort, and resources into designing their accountability systems so that they reflect the state's vision and priorities and are in compliance with federal statute. Over the course of the past year, each state has submitted its consolidated ESSA plan to the United States Department of Education (ED) and has either completed or will be completing the approval process (see https://www2.ed.gov/admins/lead/account/stateplan17/index.html). The purpose of this brief is to outline considerations for the operationalization and quality control of a state accountability system. It describes a framework that states can use to guide the development of their accountability implementation plan and put guardrails in place to validate the various outcomes of the accountability system. Please note that while the context for this brief is the implementation of each state's ESSA-based accountability system, the principles and practices apply broadly to other types of assessment and accountability systems.