TEFCA, QHINs, Carequality and CommonWell, explained
US healthcare data exchange comes with an alphabet soup — TEFCA, QHINs, Carequality, CommonWell, eHealth Exchange. They overlap, they connect to each other, and the naming does nobody any favours. Here is what each one is, how they fit together, and which one you actually need to touch.
The problem they all solve
A patient's record is scattered across every hospital, clinic, lab, and pharmacy they have ever visited. These networks exist so that an authorised organisation can find and retrieve that record from wherever it lives, under a shared legal and technical agreement — rather than negotiating a point-to-point interface with every provider in the country. Think of them as trust frameworks plus plumbing.
Carequality — a framework that connects networks
Carequality is not a network you send data through; it is a common trust framework — a legal agreement and set of technical rules that lets different networks interoperate. If two systems both implement Carequality, they can query each other without a bespoke contract. It is the connective tissue that made nationwide document exchange practical.
CommonWell — a network and vendor alliance
CommonWell Health Alliance is an actual network, founded by a group of health-IT vendors, that offers record location and query/retrieve services to its members. Crucially, CommonWell and Carequality are bridged: a participant in one can generally reach participants in the other, which is why people often mention them in the same breath.
TEFCA and QHINs — the government-backed backbone
TEFCA (the Trusted Exchange Framework and Common Agreement) is the federal effort to create a single, nationwide floor for exchange. Its backbone is a set of QHINs — Qualified Health Information Networks — vetted networks that connect to each other and carry exchange on behalf of their participants. In practice you join a QHIN (or reach one through your EHR or existing network) rather than connecting to TEFCA directly. TEFCA is steadily becoming the umbrella the older frameworks align under.
Where FHIR fits
Historically this exchange was document-based — IHE profiles such as XCA/XCPD moving C-CDA documents. The clear direction of travel is toward FHIR-based exchange, where you request discrete resources over an API instead of a whole document. TEFCA has committed to FHIR, and networks are adding FHIR endpoints alongside the document flows. If you are building today, design for FHIR while expecting to consume C-CDA for a good while yet.
What this actually means for you
- You rarely connect to any of these directly. You reach them through an EHR that participates, a network like CommonWell, or a QHIN.
- Decide what you need: nationwide query for treatment is well served by these networks; a tight, real-time feed with one hospital is still an HL7 v2 or FHIR interface.
- Handle patient matching, consent, and the "purpose of use" rules carefully — the trust framework only works if you honour them.
- Build a FHIR-first integration layer so you can meet a document-based network today and a FHIR-based one tomorrow without a rebuild.
Planning nationwide exchange? We connect applications to EHRs and interoperability networks, document- and FHIR-based. See our integration work or talk to an engineer →