HTI-1: ONC Health IT Certification Updates

HTI-1 — the Health Data, Technology, and Interoperability: Certification Program Updates, Algorithm Transparency, and Information Sharing final rule — is ONC's update to the health IT certification program. Published in January 2024 by the Assistant Secretary for Technology Policy (ASTP, formerly ONC), it modernizes what certified health IT systems must do.

If your agency uses an ONC-certified EHR or health IT system, HTI-1 defines the minimum capabilities that system must support. Think of it as the federal government raising the floor on what health IT software is allowed to call itself "certified."

HTI-1 makes several significant updates to the health IT certification program:

• USCDI v3 Adoption: Certified systems must support the United States Core Data for Interoperability version 3. This expands the standardized data set that systems must be able to send and receive — including health insurance information, clinical notes, and social determinants of health data. This is a major upgrade from USCDI v1.
• Updated API Criteria: The rule updates certification requirements for patient-facing and provider-facing APIs, aligning them with FHIR R4 and HL7 SMART on FHIR standards. This means better, more standardized API access to patient data.
• Algorithm Transparency (Decision Support): Health IT developers must be transparent about how clinical decision support tools and predictive algorithms work. This includes source data, intended use, and known limitations — particularly relevant as AI tools enter clinical workflows.
• Information Blocking Updates: The rule refines the information blocking provisions from the 21st Century Cures Act, clarifying what counts as permissible conduct versus prohibited information blocking.
• Certification Process Improvements: Streamlined certification and maintenance processes, including real-world testing requirements.

The United States Core Data for Interoperability defines the minimum data set that must flow between health IT systems. USCDI v3 significantly expands this data set compared to earlier versions.

For home health, the additions that matter most include health insurance information (critical for eligibility and prior auth workflows), clinical notes (care coordination between hospital and home health), and social determinants data (assessment and care planning).

When your software supports USCDI v3, it can send and receive a richer picture of the patient. When a hospital discharges a patient to your agency, the referral data can include more complete clinical context. When you send visit summaries back, they arrive in a standardized format the hospital system can actually parse.

Agencies don't get certified — their software does. But certification drives what your tools can do. Here is how HTI-1 affects agency operations:

• Better referral data: USCDI v3 means referring hospitals can send richer, more structured data. If your intake system can consume it, you start care with better clinical context.
• Stronger API access: Updated API certification means your software should provide better programmatic access to patient data. This enables integrations, reporting, and automation that were previously difficult.
• AI transparency: If your vendor offers AI-powered decision support (clinical alerts, risk scoring, documentation assistance), HTI-1 requires them to be transparent about how those tools work. You should know what data they use and what their limitations are.
• Vendor accountability: If your EHR vendor is dragging their feet on interoperability, HTI-1 gives you leverage. Certified systems must meet these requirements. If they don't, they risk their certification status.

These are not trick questions. Any vendor with an ONC-certified product should be able to answer them clearly:

• Is your system certified to the latest HTI-1 criteria? If not, when will it be?
• Do you support USCDI v3 today? What data elements are you missing?
• How do your FHIR APIs work? Can we access patient data programmatically?
• If you offer AI or clinical decision support tools, where can I read about how they work, what data they use, and what their limitations are?
• Have you completed real-world testing as required by the updated certification program?

HTI-1 is the foundation layer. It updates what certified health IT must do. The CMS Interoperability & Prior Authorization Rule builds on top of it by requiring payers to implement specific APIs. And HTI-4 (coming in 2027-2028) will add TEFCA requirements and additional standards transitions.

Think of it this way: HTI-1 ensures the software can speak the right language. The CMS rule ensures payers open the door. And HTI-4 connects the networks. Together, they create an ecosystem where health data flows between hospitals, agencies, payers, and patients through standardized APIs instead of faxes and phone calls.

Agencies with software built for this ecosystem will operate faster, with less friction, and with better clinical context. Agencies running legacy systems that just barely pass certification will find themselves increasingly isolated from the data flows that modern care coordination requires.