This guide has been updated to reflect various recent policy changes, many of which are new for open enrollment this year. We have added a new section highlighting key changes under "What's New for 2018" and a list of additional tools for consumers and assisters under Resources. This resource is focused solely on the private insurance reforms of the Affordable Care Act (ACA), including the health insurance marketplaces, benefit and cost structures, and premium tax credits. It is organized into four main sections that address how individuals may present themselves to Navigators based on their insurance status and coverage options. The questions and answers here have been developed in collaboration with the staff at the Center on Budget and Policy Priorities, the Georgetown University Center for Children and Families, and the Kaiser Family Foundation. This guide is intended to supplement the Navigator training available from the U.S. Department of Health and Human Services. It is not intended to be a comprehensive, stand-alone resource for all the ACA reforms. While we have made every effort to provide accurate information in this resource guide, navigators should contact their state’s marketplace, Department of Insurance, or Medicaid agency for guidance on specific circumstances. The information has been updated as of October 17, 2017.