What Happens to Your Fax Server When the PRI Goes Away?

There are thousands of fax servers operating inside healthcare organizations today that appear to be working perfectly well. The server is running, the PRI is up, faxes are moving, and the interfaces are functioning. From an IT perspective, there may be no obvious reason to touch any of it.

The concern isn’t necessarily the fax server. It’s the telecommunications infrastructure underneath it.

The telecom environment that has supported enterprise fax for decades is changing. Carriers are gradually reducing their dependence on legacy TDM infrastructure, PRI services are increasingly being grandfathered, and an increasing amount of telecommunications traffic is moving across IP-based networks. Recent FCC actions have also reduced some of the regulatory barriers that have historically slowed the retirement of legacy services.

None of this means TDM is suddenly disappearing, and it certainly doesn’t mean fax is going away. TDM continues to be an extremely effective transport for fax, and many existing circuits will likely remain in service for years. What it does mean is that healthcare organizations should begin asking a different question: What happens to our fax environment as the telecommunications infrastructure underneath it changes?

The Telecom Network Is Evolving

In March 2026, the FCC adopted rules intended to make it easier for telecommunications carriers to modernize their networks and transition away from certain legacy services. The Commission streamlined portions of the Section 214 discontinuance process, eliminated certain network-change filing requirements and addressed state requirements that can prevent carriers from retiring legacy services after federal discontinuance approval.

From the carriers’ perspective, the motivation isn’t difficult to understand. Maintaining multiple generations of network infrastructure is expensive, particularly as more communications move to IP-based networks. That doesn’t make TDM bad technology. It simply means the telecommunications ecosystem is evolving into an increasingly hybrid environment in which TDM and SIP coexist, while investment and growth are increasingly concentrated on IP.

For a healthcare organization with critical fax workflows connected to a PRI, that transition deserves attention.

Lumen Has Grandfathered PRI

CenturyLink, part of Lumen, states that its ISDN Primary Rate Interface service was grandfathered effective July 1, 2026 and is no longer available as a new service in all CenturyLink states. CenturyLink has also grandfathered other traditional telecommunications products, including ISDN BRI, Direct Inward Dialing and PBX trunk services.

Grandfathering doesn’t mean an existing PRI suddenly stops working. In many cases, those circuits may continue operating reliably for years. The more important issue is what happens when an organization needs to change something. A grandfathered service may become difficult or impossible to expand, replicate at a new location, modify or replace on the same terms.

For an IT department planning infrastructure five or ten years into the future, that’s an important distinction. A system can be completely reliable today while still becoming increasingly difficult to support tomorrow.

Other Carriers Are Moving in the Same Direction

Lumen isn’t alone. AT&T has been transitioning portions of its network from TDM to IP and has grandfathered traditional services in various markets. In California, for example, AT&T’s Primary Rate ISDN became unavailable for purchase by new or existing customers effective February 23, 2026, with restrictions on moves, additions, changes and renewals.

Verizon has also restricted certain new PRI arrangements while continuing its broader network modernization efforts. The timelines, technologies and policies vary considerably by carrier and geography, so there isn’t a single nationwide date when PRI or TDM suddenly disappears.

Instead, we’re seeing a gradual transition toward an environment in which TDM and SIP coexist, but the availability and economics of traditional telecom services are changing. That creates a different kind of risk for healthcare IT: not necessarily that a PRI stops working tomorrow, but that an organization discovers at the worst possible time that the infrastructure it has relied on for years can no longer be expanded or reproduced.

Your Fax Server May Be Fine. The Dependency Is the Risk.

Healthcare isn’t abandoning fax, nor should modernization automatically mean replacing fax with another document exchange technology. Fax continues to solve an interoperability problem that many newer healthcare exchange technologies have struggled to solve universally: almost everyone can receive one.

A hospital doesn’t need to know which EHR a physician practice uses before sending a fax. A referral coordinator doesn’t need to determine whether the receiving organization participates in the same exchange network, and back-office staff don’t need to search for the correct Direct address or understand another organization’s technology environment. They need a fax number.

That simplicity and universality remain enormously valuable in a healthcare ecosystem made up of thousands of organizations using different applications, networks and workflows.

The potential weakness isn’t fax itself. It is designing a mission-critical fax environment around a small number of telecommunications dependencies that the healthcare organization doesn’t control. A traditional LAN-based fax environment may depend on a particular PRI, carrier, gateway and data center. When everything works, that architecture can be extremely reliable. When a facility moves, capacity needs to increase, hardware fails or the carrier changes the underlying network, those dependencies can suddenly become very visible.

Cloud Fax Changes Who Has to Manage That Complexity

Moving fax to the cloud shouldn’t be viewed simply as replacing TDM with SIP. That’s an oversimplification of how reliable fax delivery actually works.

WestFax continues to operate TDM infrastructure, including grandfathered TDM connectivity that remains valuable to our network. At the same time, an increasing percentage of fax traffic is being successfully transported over SIP and modern IP telecommunications networks. We expect that balance to continue changing over time.

The important difference is that a WestFax customer doesn’t have to decide which technology ultimately wins.

The future of fax isn’t necessarily TDM or SIP. A better model is having access to both, across multiple telecommunications carriers, and having the intelligence to determine which path provides the greatest likelihood of successfully completing a particular fax.

That is fundamentally different from operating a fax server connected to a PRI from a single carrier at an individual hospital or data center.

Not Every Fax Should Take the Same Route

Fax delivery becomes more complicated at scale than many people realize. Different carriers, destination networks, endpoints, media gateways and SIP implementations can behave differently, and a route that works extremely well for one destination may not be the optimal route for another.

This is one of the major advantages of the WestFax network. Rather than depending on a single telecommunications provider or transport method, we maintain a diverse carrier network with both TDM and SIP connectivity. That gives the platform multiple potential paths for completing a fax instead of forcing every transmission through the same carrier and network architecture.

WestFax AI routing adds another layer to that network diversity. Our routing technology can use information developed across fax traffic to help determine when SIP is the appropriate path and when TDM is more likely to produce a successful result. As network conditions and carrier performance change, the routing strategy can change with them.

The objective isn’t to prove that SIP is better than TDM, or vice versa. The objective is to complete the fax.

For healthcare, that’s ultimately the metric that matters.

Network Diversity Matters More Than the Acronym

A healthcare organization doesn’t send a referral because it wants to use PRI, SIP or TDM. It sends the referral because another provider needs the document. The same is true for prior authorizations, lab orders, prescriptions, records requests and the countless other documents moving through healthcare every day.

When one of those transmissions fails, somebody usually has to deal with it. Staff may need to identify the failure, resend the document, call the recipient or otherwise intervene. At healthcare scale, even a relatively small difference in fax completion rate can translate into a significant amount of administrative work.

This is why carrier diversity is so important to the WestFax architecture. An on-premises fax server connected to a PRI has essentially made several routing decisions in advance: one circuit, one carrier and one primary path into the telecommunications network. A cloud platform with diverse carrier relationships and multiple transport options can make those decisions much more dynamically.

If one route isn’t performing well, another may be better. If a destination behaves more reliably over TDM, that option remains valuable. If SIP provides an efficient and reliable path, the network can take advantage of it. The customer doesn’t need to manage those decisions because the cloud platform manages them underneath the fax service.

That diversity is one of the reasons WestFax can focus so intensely on fax deliverability rather than simply fax transmission.

This Is What Makes Cloud Fax Future-Oriented

The case for cloud fax becomes much more compelling when it’s viewed as an architectural decision rather than merely a way to eliminate a server.

A healthcare organization shouldn’t have to predict what Lumen, AT&T, Verizon or another carrier will do with a particular telecom product five years from now. It shouldn’t have to decide how quickly SIP will replace portions of TDM infrastructure or maintain specialized expertise internally to continually adapt its fax environment as those networks evolve.

That responsibility can move to the cloud provider.

As telecommunications networks change, WestFax can change with them. More traffic can move over SIP where SIP performs well, while TDM can remain available where it continues to provide an effective path. Carrier relationships can evolve, routes can change and new network technologies can be incorporated without requiring every hospital, physician group or healthcare company to redesign its own fax infrastructure.

That’s the larger promise of cloud fax: separating a durable healthcare workflow from the constantly changing telecommunications technology underneath it.

The Opportunity Goes Beyond Transport

There is another important reason to consider this transition now. Simply moving an existing fax workload from an on-premises server to the cloud captures only part of the opportunity.

Fax is extraordinarily effective at getting documents between organizations, but historically the information inside those documents has required a tremendous amount of human intervention. Someone receives the fax, determines what kind of document it is, identifies the patient, decides where it belongs and routes it into the appropriate workflow.

With WestFax Orchestrate, OCR, document intelligence and AI can begin automating those processes. Instead of treating every incoming fax as an image waiting for a person to interpret it, the platform can help identify, classify and route documents into the appropriate workflow.

This creates two complementary layers of intelligence. On the network side, AI-assisted routing can help select between carriers and transport technologies to improve fax completion. On the workflow side, AI and document intelligence can help determine what an incoming document is and where it should go.

The fax number remains simple and universal for the sender. Everything behind it becomes considerably more sophisticated.

Don’t Let a PRI Decision Become a Fax Emergency

Healthcare organizations don’t need to panic about PRI retirement, but ignoring the changes taking place in telecommunications isn’t a sound long-term strategy either.

Organizations operating LAN-based fax servers should understand when their PRI contracts expire, whether additional capacity can still be ordered, whether existing circuits can be moved, what happens when a new facility opens and what alternatives exist if the carrier changes the underlying network. They should also consider a question that is often overlooked: How many independent telecommunications paths does our fax environment actually have if our primary route begins experiencing problems?

The answers may show that there is no immediate issue, which is precisely when an organization has the greatest flexibility to plan a migration rather than react to one.

Fax Has a Future. Its Infrastructure Is Changing.

There have been predictions for years that newer healthcare exchange technologies would eliminate fax. Yet fax remains deeply embedded in healthcare because it provides something extraordinarily difficult to reproduce across a fragmented industry: a ubiquitous method of exchanging documents that doesn’t require both organizations to use the same EHR, participate in the same network or maintain compatible directories.

The telecommunications infrastructure underneath fax is changing, but that doesn’t diminish the value of fax. If anything, cloud technology creates an opportunity to make fax more resilient by combining the reach of fax with multiple carriers, TDM and SIP connectivity, intelligent network routing, AI-assisted document processing and an architecture that can continue adapting as telecommunications technology evolves.

For healthcare organizations still operating fax servers behind PRIs, the question isn’t whether the fax workflow remains valuable. It clearly does.

The question is whether it still makes sense to tie that workflow to a telecommunications architecture that is becoming harder to expand, replace and predict.

Keep the interoperability of fax. Move the infrastructure to the cloud. And let a diverse, intelligent network determine the best path for getting each document where it needs to go.

Frequently Asked Questions