PHIN Public Health Directory


Directory services are one of the core infrastructure components of any enterprise information architecture. The PHIN Public Health Directory (PHIN DIR) performs this essential service in the context of PHIN. It is a repository of information about organizations and jurisdictions important to public health programs and provides Object Identifiers (OIDs) for use within the public health community.

PHIN DIR is not a single directory but is a distributed network of related directories. Every PHIN partner organization – state health departments, larger local health departments, and CDC – needs to own and manage its own directory. Every partner organization has sole responsibility for maintaining information about its own workforce, and about the people and organizations within its jurisdiction that play a role in PHIN systems or in the partner’s emergency response plan.

In recognition of the unique circumstances and constraints around each PHIN partner organization, there are no requirements specifying how a Public Health Directory system must be implemented. It is not important that various partners’ directory systems use a particular technology, or even that they share a common internal data schema.

Instead, the PHIN DIR requirements focus on:

  • the kind of people, roles, and organizations that must be maintained in each partners’ directory
  • the kind of information about these people, roles, and organizations that must be kept in each directory, and that must be shareable with other partners
  • the ability of the directory system to serve other system internally (notably, PHIN Communication and Alerting (PCA))
  • the ability of partners’ systems to electronically exchange key information about key people and organizations with each other

While PHIN DIR poses no requirements as to how a directory system represents, structures and stores information, it does specify an XML-based schema for directory exchange messages that systems must be able to both produce and consume, as well as the use of a specific message transport protocol (PHIN MS). The attributes within the directory exchange message schema, in turn, do place some requirements on the type of information stored within each directory, however, this required information is so fundamental that it is highly likely to already be present.

While every organization will decide how much information about its own workforce to expose to the public, PHIN DIR is not intended to be a publicly accessible resource, and partners are especially bound to safeguard the privacy of information received from partner organizations.

Partners are encouraged to integrate their Public Health Directory implementation with any other enterprise-level directory services that may exist. Compared to the typical proliferation of separately operated and maintained directory databases, a centralized directory service reduces overall maintenance effort by eliminating redundancy, improves information accuracy and currency, and provides better and uniform service to multiple critical application systems.

An enterprise level directory can:

  • Support manual lookup of information on people and organizations for routine communication and other purposes
  • Allow application systems to automatically look up people and organizations, and/or create and manage information in the directory
  • Support user authentication (system sign on) process
  • Support control of people’s access to information and systems

Implementation Guide

The PHIN Directory Exchange Implementation Guide and all implementation guides that are in Final format can be viewed on the Guides page.

Page last reviewed: December 2, 2019