In 2013, The Andrew W. Mellon Foundation awarded a group of seven librarians from the Research Library Leadership Fellows program of the Association of Research Libraries (ARL) a planning grant to examine the center of excellence (CoE) model for information services. Used in a variety of industries, CoEs are designed to attract the most talented researchers in a particular field, enhance collaboration, and improve access to the resources needed for their research. The planning grant was awarded to determine whether the CoE model could serve as a means to provide the new services required for the effective use of digital information. This report describes the team's approach to examining the feasibility of CoEs in the library setting. The team conducted preliminary investigations of more than 100 centers, which they narrowed to 35 for in-depth research. Interviews were conducted with staff at 19 centers and 7 funding organizations. In their conclusion, the team advises developing "networks of expertise" or "expert networks," instead of CoEs, and provides a series of recommendations for building such networks. The following are appended (1) Centers and Funders Interviewed; and (2) Questions for Interviews.