The Limits of Interoperability: What the 21st Century Cures Act solved, and what it didn’t.
The creation of the 21st Century Cures Act marked a defining moment in U.S. health IT policy. At its core, the legislation and the subsequent rules stewarded by the Office of the National Coordinator for Health Information Technology (ONC) sought to correct a structural imbalance in healthcare: data existed, but it was trapped. Patients could not easily access their records. Providers struggled to exchange information across systems. Innovation was stifled by information blocking and proprietary control.
In many respects, the act succeeded. It forced long-overdue progress around standardized APIs, patient access, and the expectation that electronic health information should be portable, computable, and accessible. Electronic Health Record (EHR) vendors were clearly in scope. Administrative data, clinical documentation, medications, problems, allergies, and laboratory results became first-class citizens in the interoperability conversation.
But the success of the Cures Act also reveals its blind spots— especially as the industry pushes toward more complete healthcare interoperability.
Why does the definition of “health information” still feel too narrow?
The regulatory framework that emerged from Cures was shaped; intentionally or not; by the EHR-centric view of healthcare data. ONC certification criteria, information blocking rules, and API mandates overwhelmingly target systems of documentation rather than systems of observation.
Physiologic data streams from bedside monitors, ventilators, infusion pumps, smart beds, and other networked devices are foundational to clinical decision making; yet are not treated with the same urgency or expectation for accessibility as discrete EHR data elements. Continuous waveforms, high-frequency numerics, and time-synchronized device data remain inconsistently governed, inconsistently retained, and inconsistently shared.
This is not a trivial omission. It represents a structural disparity in how we value different classes of clinical data. This disparity limits both EHR interoperability and broader healthcare interoperability.
Who is impacted by the Cures Act and who is not?
The technologies most directly impacted by the 21st Century Cures Act are those that already sit at the center of healthcare’s administrative gravity:
- Certified EHR platforms
- Patient portals and consumer-facing apps
- Health information exchanges (HIEs)
- Clinical documentation and order-entry systems
These systems are now accountable for openness, standardization, and patient access. This shift has reduced information blocking in healthcare for these specific systems.
By contrast, many device ecosystems are not:
- Physiologic monitors and telemetry systems
- Ventilators and anesthesia machines
- Infusion pumps and smart beds
- High-resolution waveform capture platforms
These technologies often operate in parallel to the EHR; deeply embedded in care delivery, yet lightly regulated from an interoperability standpoint. Their data may be summarized, delayed, transformed, or never exported at all. In practice, this means that the most actionable physiologic signals are often the least portable.
The consequence: A Two-Tier Data System
The result is a two-tier model of interoperability
On one tier, discrete clinical facts including labs, meds, and diagnoses flow relatively freely, governed by modern APIs and regulatory teeth. On the other hand, physiologic truth exists in silos: ephemeral, device-bound, and difficult to reuse for quality improvement, research, AI development, or longitudinal care.
This disparity matters. Advanced analytics, predictive modeling, virtual care, and AI-enabled medicine depend on continuous, high-fidelity physiologic data. Yet the policy framework that champions data liquidity largely sidesteps the very data required to power healthcare’s next generation.
Without device level data, healthcare interoperability remains fundamentally incomplete.
A call for the next chapter: What needs to change to reduce information blocking in healthcare?
To be clear, this is not an indictment of ONC or the 21st Century Cures Act. The act addressed the most immediate and visible bottleneck of its time. As healthcare has evolved, however, so must our definition of interoperability.
If interoperability is truly about improving outcomes, enabling innovation, and empowering patients and clinicians, then physiologic data and medical devices can no longer remain peripheral. The next chapter of national coordination must expand its scope beyond documentation systems to the systems that observe the human body in live action.
Until then, interoperability will remain incomplete, not by accident, but by omission.
