One limitation of EHR immunization reminders is that they generally act only on local EHR immunization data. If that data is incomplete, a provider may be erroneously alerted to order an immunization the child does not need. The likelihood of incomplete local data is high. Nearly one-quarter of children in the U.S. visit more than one immunization provider in their first three years of life, leading to fragmented and incomplete records. Low-income and minority children are especially susceptible to immunization record fragmentation as they are more likely to receive care from multiple clinics and providers. Children with CMCs are also at high-risk since their care is often shared between a primary care provider and subspecialists.Harnessing Immunization Information Systems (IIS) data can help overcome this limitation. IIS are population-based systems that collect immunization data primarily for children and adolescents from providers at a regional or state level, consolidating patient's immunization data into a single location no matter where administered. There are currently IIS in 50 states, five cities, and the District of Columbia. However, in most cases, IIS data are available to providers only on the IIS's website. Yet, frontline care providers are most likely to benefit when an IIS provides information at point of patient care within their EHR workflow. This type of bidirectional exchange of immunization information between IIS and EHR systems is a proposed Stage 3 Meaningful Use objective; this consolidated data would be the most complete data to use for an EHR reminder, but is rarely used.