The advanced access model of patient scheduling is based on the core principle that if the capacity to provide patient appointments balances the demand for appointments, patients calling to see their physician are offered an appointment the same day. The accompanying article in the series "Innovations in Primary Care" presents the theory behind advanced access scheduling. In this article we describe 4 case studies of primary care practices that successfully implemented advanced access and 3 examples of practices that were unable to achieve advanced access despite considerable efforts. The lessons of these case studies should be useful for primary care practices desiring to improve timely access to care and wishing to avoid the pitfalls that can derail this innovation.