Charles August Long Undiagnosed Diseases Research and Collaboration Network Act of 2013 or CAL Undiagnosed Diseases Research and Collaboration Network Act of 2013 - Requires the Director of the National Institutes of Health (NIH) to establish and maintain an undiagnosed diseases patient network. Includes among the purposes of the CAL Network to: (1) provide physicians who are handling cases of undiagnosed diseases with a means to search for similar cases and to network and collaborate with physicians handling similar cases, (2) better enable and examine cross-disease research, (3) better describe the types and prevalence of cases of undiagnosed diseases in the United States, and (4) provide such data necessary to better understand the length of time for a diagnosis to be rendered and to identify barriers to diagnoses and reasons for misdiagnosis of diseases.

Authorizes the Secretary of Health and Human Services (HHS) to award grants to, and enter into contracts and cooperative agreements with, public or private nonprofit entities for: (1) the collection, analysis, and reporting of data on cases of undiagnosed diseases and other disorders that can often go undiagnosed or be misdiagnosed as other diseases or disorders; and (2) the establishment of separate undiagnosed disease programs.