United States Core Data for Interoperability (USCDI)

Key facts

Maintained by

HHS Assistant Secretary for Technology Policy and ONC (ASTP/ONC)

First adopted

ONC 21st Century Cures Act Final Rule (2020)

Replaced

The Common Clinical Data Set in certification criteria

Regulatory home

Health IT certification program rules at 45 CFR Part 170

Update cycle

New version usually published each July after public comment

What is USCDI?

The United States Core Data for Interoperability (USCDI) is a list of the health data that certified health IT should be able to exchange in a standardized way. It groups data elements, such as a medication or a lab result, into data classes and names the vocabulary standards each element should use.

The Office of the National Coordinator for Health Information Technology (ONC), now organized within the HHS Assistant Secretary for Technology Policy (ASTP/ONC), maintains USCDI. The ONC 21st Century Cures Act Final Rule adopted it in 2020. USCDI does not specify how data moves; implementation guides such as FHIR US Core and C-CDA define that.

How USCDI is organized and updated

USCDI is organized into data classes. Examples include:

ONC publishes a new version roughly once a year. Adoption into certification requirements happens separately through rulemaking: the HTI-1 final rule, released in December 2023 and published in January 2024, made USCDI version 3 the baseline for certified health IT starting January 1, 2026. Developers may adopt newer versions voluntarily through the Standards Version Advancement Process.

• Patient demographics, such as name, date of birth, race, ethnicity and preferred language.
• Problems, coded in SNOMED CT or ICD-10-CM.
• Medications, coded in RxNorm.
• Laboratory tests, coded in LOINC.
• Allergies and intolerances, immunizations, procedures, vital signs, clinical notes and health insurance information.

Why USCDI matters

USCDI defines the minimum shared data model of U.S. health IT:

• It sets the data that patients, providers and apps can expect to retrieve from certified EHRs through FHIR APIs.
• Health IT and AI companies can design data pipelines around USCDI elements and their required vocabularies instead of vendor-specific fields.
• CMS payer interoperability rules reference USCDI for clinical data shared through patient access and payer-to-payer APIs.
• Program-specific extensions, known as USCDI+, build on it for areas such as public health, quality measurement and research.

Limitations of USCDI

USCDI is a floor, not a ceiling, and it describes what systems must be able to exchange rather than what every record contains. A certified system can support an element that clinicians rarely fill in, so data completeness still varies widely between organizations. Federal health IT rules are also revised often, so certification deadlines should be checked against current ASTP/ONC rulemaking.