As a nation, we have yet to grasp the full benefits or unwanted effects of artificial intelligence. AI is widely used, but how do we know it's working appropriately? This report identifies key accountability practices—centered around the principles of governance, data, performance, and monitoring—to help federal agencies and others use AI responsibly. For example, the governance principle calls for users to set clear goals and engage with diverse stakeholders. To develop these practices, we held a forum on AI oversight with experts from government, industry, and nonprofits. We also interviewed federal inspector general officials and AI experts.