Facilitating a robust system of communication and coordination between medical and community service providers, an important goal of many health care delivery system reforms, is challenging for many states. With a variety of federal and state agencies sharing responsibility for child health and development, creating effective linkages among services is critical to optimizing outcomes. This issue resonates strongly with state Medicaid and Part C Early Intervention (EI) agencies, which are responsible for creating comprehensive systems of care that coordinate a wide range of services to support healthy child development. To ensure children receive timely access to necessary care within the scope of limited state budgets, Medicaid and EI agencies must establish carefully articulated processes for medical and community-based service providers to deliver developmental screening, referral, and follow-up services. Building stronger partnerships between Medicaid and EI agencies can facilitate better coordination of these services to expedite the referral and follow-up process, helping agencies adhere to federally mandated timelines and enabling children and families to receive more timely services. Strong partnerships between these agencies are also key to avoid excess costs that result from duplicative services. This issue brief provides concrete examples of how Medicaid and EI agencies in Connecticut, Illinois, and Oregon have partnered to improve care for young children in their states who are identified with, or at risk for, developmental delays. A forthcoming companion brief will closely examine Medicaid screening reimbursement policies in several leading states.