Reference models to federate enterprise architectures across multiple agencies are investigated as a means to provide greater mission effectiveness and increased efficiencies. While heuristic and qualitative approaches to federating enterprise architectures have led to the increased use of reference models, their actual effectiveness and value have not been quantified. Federal departments and agencies are under increasing pressure to provide effective government and citizen services with improved efficiency. Enterprise architectures are used to align agencies’ strategic goals and business objectives to resources. As agencies collaborate with each other to achieve better strategic performance and resource savings, the ability to share information about their enterprise architectures is critical to their success. The expected effectiveness of reference models in federating enterprise architectures was quantified employing the classical method of expert judgment. A structured discussion instrument to evaluate reference models was developed and piloted using well-established guidelines for expert judgment. The resulting instrument was used in structured discussions with architects and engineers who are members of an architecture working group across multiple federal government agencies. Reference models were determined to be effective for federating enterprise architectures where participating agencies align their component architectures to the common taxonomy provided by the reference models.