By Lisa Nelson, Chief Technical Officer, and Alex Young, Director of Technical Operations

When you think about interoperability, chances are you picture data exchange – clinical summaries, referrals, patient records moving from one system to another. But none of that works without knowing where to send the information and how to find the right recipient.

For years, the DirectTrust® Directory has powered secure exchange through Direct Secure Messaging. But like any tool that’s been around a while, it needed more than a tune-up – it needed a rethink. That rethink began in earnest in 2020 and has grown into a full-scale transformation of the Directory’s technical foundation, data quality practices, and policy framework. Now, the Directory isn’t just more robust – it’s more useful, more accurate, and better aligned with the real-world needs of interoperability today.

Why the Directory Needed to Improve

The DirectTrust Directory is an essential piece of the Direct Secure Messaging ecosystem. It’s where clinician Direct addresses live, and where healthcare professionals go when they need to find an address to send information securely. Over time, however, the DirectTrust community recognized the Directory wasn’t delivering the full value it could.

Directory uptake was limited, partly due to many of the addresses in the Directory being outdated or incomplete. Some Directory entries were duplicates or didn’t reflect how care was delivered. The structure of the Directory entries lacked the expressivity and flexibility needed for today’s use case-based interoperability demands. In 2020 it was determined the technology powering the DirectTrust Directory needed a lift to improve its structure, content validation, and utilization.

The solution wasn’t a single fix, but a phased plan involving technical redesign, community education, and potential policy changes.

The Technical Overhaul

The first phase of improvement focused on the technology. Our team at DirectTrust restructured the Directory to use a standardized, FHIR-based format, bringing it into alignment with national directory standardization efforts and dramatically improving how Directory entries were organized and accessed. What had once been flat rows of information would be transformed into standard FHIR resources with relationships between organizations, locations, and practitioners with endpoints (Direct addresses) associated to the right parts of the structure – which is more reflective of how healthcare actually works.

We also implemented over 60 new validation rules to improve the quality of submitted data. These checks range from NPI validation to flagging missing fields or inconsistent entries. Now Health Information Service Providers (HISPs) receive detailed reports that highlight data quality issues with their submissions, explaining the needed correction.

Another major milestone was adding the ability to support incremental updates. Previously, HISPs had to re-upload all of their Directory entries each time they refreshed their contribution. Now they can submit only what’s changed – a smaller set of deletions and additions – which reduces administrative burden while keeping the data fresher.

Still, even after all these updates, desired usage continued to lag. The tech worked, but it wasn’t being used to its full potential. That told us that it was time to go further and look beyond the tools.

The Education Gap

Technology can only go so far if users don’t understand how the Directory works or what it can do. That’s why a parallel education initiative was launched, helping stakeholders understand and rethink how Direct addresses should be used and shared.

One key shift was to move from a “white pages” mentality (listing individual clinicians) to a “yellow pages” one (including departmental and workflow-specific addresses that reflect real operational needs). For example, referrals shouldn’t be sent to Dr. Smith’s personal inbox; instead, they should go to a Direct address established to efficiently process referrals for Dr. Smith’s practice.

Further, thanks to the FHIR-based Directory model, we now can support more metadata per endpoint. New use case codes have been established to clarify what each Direct address is meant to support (e.g., referrals, ADT notifications). This provides valuable context for Directory entries and makes the Directory a more powerful lookup resource.

When Technology and Education Isn’t Enough, Adjust Policies

Two years into the Directory Improvement Initiative, the DirectTrust community wasn’t seeing the level of improvement they wanted organically, causing the DirectTrust’s Directory Policy Workgroup, which includes HISPs, vendors, providers, and technical experts, to identify a set of policy drivers to help reach the desired outcomes. The changes included:

  • Mandatory participation in the Directory for all HISPs
  • At least one Direct address included in the Directory per organization (encouraging a Directory Steward entry to ensure a pathway for further improvement in Directory content)
  • HISP contributions required every 72 hours for the latest Directory entry content
  • HISP downloads and redistribution of the DirectTrust Aggregated Directory to customers required every 72 hours
  • Public access permitted to a new limited-use Directory search tool on the DirectTrust website, demonstrating use of new FHIR APIs supported by the updated Directory
  • Ability to collaborate with organizations on Directory initiatives to fuel interoperability

These requirements and changes were made through policy updates and tied to HISP accreditation, which created a clear incentive – and it worked. We saw 100% HISP participation, better quality data, and a significant increase in Direct address awareness and overall usage of Direct Secure Messaging. This included a surge in the number of Direct addresses in the Directory, which peaked at over 1.3 million before stabilizing at 1.2 million, and a 42% rise in message volume across the network in 2024.

What’s Next

DirectTrust is now preparing for the next round of improvements. As of mid-2025, we’re entering a new planning phase, which includes gathering input from across the ecosystem to identify emerging needs and ongoing challenges. The goal is to develop an annual improvement cycle that incorporates feedback, updates the Directory’s capabilities, and maintains momentum.

This summer, at the DirectTrust Annual Conference in St. Louis, we’ll unveil the proposed plan for our next improvement cycle – gathered from months of listening, feedback, and hands-on collaboration. It’s your chance to weigh in, share your needs and help guide what comes next.

We want to say thank you to the HISPs, vendors, organizations, and volunteers who’ve already helped us move the needle. If you’ve ever wondered whether a national directory can truly improve – this is your answer. Together, we’ve proven it’s possible. DirectTrust continues to collaborate with organizations throughout the healthcare ecosystem to explore innovation that expands the scale of this existing asset and leverages DirectTrust’s experience in Directory maintenance and governance.

The DirectTrust Directory has come a long way. It’s no longer flat, stale, or awkwardly aligned with the organizational uses of Direct Secure Messaging. Now it’s more structured and searchable, offering trusted endpoints with greater usability and scalability that’s ready to grow with the industry in exciting new ways. Attend the DirectTrust 2025 Annual Conference to find out more about the roadmap forward!