Estimating impact of ARR on HIE enrollees: The Auto-Reenrollment and Renewal (ARR) policy on the Health Insurance Exchanges (HIEs) was designed to prevent unintentional discontinuous enrollment among HIE enrollees by automatically reenrolling enrollees in their default health plan if an active selection was not made during open enrollment. However, in the five years since ARR was implemented, policymakers have become concerned that ARR is enhancing consumer inertia that is then distorting market signals on the HIEs and increasing premiums, and have considered modifying ARR. The purpose of this research is to establish the impact of ARR on consumer inertia and consumer welfare within HIEs.