The interoperability vocabulary, in plain English

CMS Interoperability and Prior Authorization Final Rule

CMS-0057-F requires impacted US payers to stand up four FHIR APIs — Patient Access, Provider Access, Payer-to-Payer, and Prior Authorization (PARDD) — with API compliance generally due January 1, 2027.

Prior Authorization Requirements, Documentation, and Decision API

PARDD is the CMS-0057-F Prior Authorization API that lets providers query coverage requirements, gather documentation, and submit and track authorization decisions via FHIR.

A FHIR-based API that automates the prior-authorization workflow — checking requirements, gathering documentation, and exchanging decisions — as required by CMS-0057-F.

HL7 Version 2.x

HL7 v2 is the pipe-and-hat messaging standard that still carries most real-time clinical data between hospital systems — admissions, orders, results, and more.

Fast Healthcare Interoperability Resources

FHIR is HL7's modern, web-native standard for exchanging healthcare data as modular JSON/XML resources over RESTful APIs.

US Core Implementation Guide

US Core is the HL7 implementation guide that constrains FHIR resources into the specific profiles US regulation requires, binding them to USCDI data elements.

United States Core Data for Interoperability

USCDI is the ONC-maintained, versioned list of data classes and elements that must be available for nationwide health information exchange.

Consolidated Clinical Document Architecture

C-CDA is the HL7 XML standard for clinical documents such as the Continuity of Care Document, discharge summary, and referral note.

ASC X12N 278 Health Care Services Review

X12 278 is the EDI transaction US payers use for prior-authorization and referral requests and responses.

HL7 Da Vinci Project

Da Vinci is the HL7 accelerator that publishes FHIR implementation guides for payer–provider workflows, including prior authorization, coverage, and data exchange.

Flat FHIR / FHIR Bulk Data

Bulk FHIR is the FHIR Bulk Data ("$export") specification for efficiently moving large populations of FHIR resources as NDJSON, used for analytics and payer-to-payer exchange.

Admit, Discharge, Transfer messages

ADT is the family of HL7 v2 messages that communicate patient admissions, discharges, transfers, and demographic updates — the most common real-time feed in a hospital.

Trusted Exchange Framework and Common Agreement

TEFCA is the US framework that connects health data networks nationwide through a common legal and technical agreement, operationalized by QHINs.

Qualified Health Information Network

A QHIN is a network designated under TEFCA to exchange health data nationwide with other QHINs on behalf of its participants.

SMART App Launch

SMART on FHIR is the OAuth 2.0 / OpenID Connect authorization framework that lets third-party apps securely launch against a FHIR API with scoped access.

Enterprise Master Patient Index

An EMPI resolves whether records from different systems refer to the same person, using probabilistic matching to link identities without a shared identifier.

NCPDP SCRIPT Standard

NCPDP SCRIPT is the national standard for electronic prescribing transactions between prescribers and pharmacies.

Real-Time Prescription Benefit

RTPB surfaces patient-specific drug coverage and out-of-pocket cost inside the prescribing workflow, so clinicians can pick affordable, covered medications at the point of care.

RxNorm is the US normalized naming system for clinical drugs, providing standard identifiers that let different medication vocabularies interoperate.

National Drug Code

The NDC is the FDA identifier for a specific drug product at the package level — identifying manufacturer, product, and package size for dispensing and billing.