HL7 Connectathon events bring vendors together to test their Da Vinci IG implementations against each other in realistic integration scenarios. The results expose what works in practice across vendor pairs, not just what passes Inferno tests in isolation. For health plans evaluating Da Vinci vendors in 2026, Connectathon participation and results are a strong signal of real production capability. Five aspects of Connectathon results are worth examining during vendor selection. For the CMS interop architecture series on this site, these are the practical evaluation criteria.
1. Multi-Vendor Round-Trip Demonstrations
The most important signal. A Da Vinci CRD service interoperating with a different vendor's EHR. A DTR SMART app launching inside an EHR from a third party. A PAS Bundle submitted from one vendor and processed by another. The round-trip across vendor boundaries is what production Da Vinci deployments actually require.
Vendors who can demonstrate multi-vendor round-trips at Connectathons have evidence of integration capability that single-vendor demos do not. Vendors who only show their own stack interoperating with itself have less evidence.
2. Inferno Pass Rates Under Connectathon Pressure
Inferno pass rates in controlled testing tell one story. Pass rates during Connectathons (where multiple things are happening at once, integration scenarios are running, and time pressure is real) tell a more honest story.
Vendors whose Inferno pass rates degrade during Connectathon have something brittle in their implementation. Vendors whose pass rates stay high have more confidence in production deployment.
3. Edge Case Handling Across Vendor Boundaries
Connectathon results often include edge cases that planned testing does not surface. A Patient resource missing optional fields. A Coverage resource with an unusual subscriber-member relationship. A PAS Bundle with attachment formats that one vendor handles fluently and another rejects.
The edge case handling matters because production data contains edge cases. Vendors who handle Connectathon edge cases gracefully are more likely to handle production edge cases gracefully.
4. CDS Hooks Card Rendering Across EHR Platforms
A specific Connectathon result worth examining. The payer's CDS service returns cards to multiple EHR vendors' implementations of CDS Hooks. Does the card render consistently? Does action button behavior work the same across EHRs? Do the cards survive the EHR-specific quirks that Inferno does not test?
For payers planning to deploy CDS services across diverse EHR networks (Epic plus Cerner plus athenahealth plus smaller EHRs), the cross-EHR rendering consistency at Connectathons predicts production behavior.
5. Member Match Accuracy Across Synthetic Data Sets
Connectathon Member Match testing uses synthetic patient sets with known variations. The vendor pairs (receiving payer, prior payer) attempt matches, and the results are scored against the ground truth. Match accuracy varies substantially across implementations; the Connectathon data is one of the few public sources of comparative accuracy information.
For payers building Payer-to-Payer Data Exchange, Member Match accuracy is load-bearing. Connectathon results are stronger evidence than vendor marketing claims about match performance.
What Vendor Connectathon Participation Actually Signals
The participation pattern matters as much as the results. Vendors who show up regularly to Connectathons, document their work publicly, and demonstrate progress across events are investing in real production capability. Vendors who skip Connectathons or only attend selectively may be less prepared for the integration complexity that production CMS-0057-F deployment will surface.
A useful check is to ask the vendor for their Connectathon history: which events, which IGs tested, which counterparts they worked with. Vendors with substantive answers are more credible than vendors who hedge.
How to Use Connectathon Data in Vendor Selection
The honest framing is that Connectathon results are one signal among several. They do not replace Inferno conformance, production customer references, or technical evaluation. They do provide signal that other sources do not: real cross-vendor integration capability and edge-case handling under realistic pressure.
For the broader Da Vinci IG landscape that Connectathons test, the Top 6 Da Vinci IGs every health plan should track in 2026 covers the IGs. For the Inferno conformance side of the testing picture, the Top 5 Inferno conformance patterns for Da Vinci implementations covers the formal testing layer.