Clinical systems · Payer FHIR interoperability platform
Onyx
Onyx makes OnyxOS, a FHIR platform that runs the CMS interoperability and prior authorization APIs for health plans and state Medicaid programs.
Strong fit
- Health plans and Medicaid agencies working through CMS-0057
- Plans that want prior authorization APIs and services in one contract
- Azure-based IT teams
Weak fit
- Provider groups and digital health vendors
- Buyers who need a public price list
- Teams that want to build on open source
Bottom line
Onyx is a reasonable pick for health plans and state Medicaid programs that want CMS-0057 APIs and expert services from the team behind Blue Button 2.0. It is narrow outside payer compliance. Buyers should confirm cost and timeline in writing.
Score breakdown
Weights: Outcomes 35% · Product 30% · Implementation 20% · Pricing clarity 15%.
Onyx Technology launched in May 2020 as a subsidiary of NewWave, the contractor that built the CMS Blue Button 2.0 API for Medicare. Susheel Ladwa, who held leadership roles at IBM and Wipro, is chief executive.
Mark Scrimshire, its chief interoperability officer, was the architect of Blue Button 2.0 and an author of the HL7 Da Vinci PDex standard that CMS-0057 builds on. Grahame Grieve, who created FHIR, advises the company.
OnyxOS covers the patient access, provider access, payer-to-payer and prior authorization APIs that CMS-0057 requires. It also runs provider directory data for Medicare Plan Finder and monitors each API after go-live.
Onyx says it serves more than 50 health plans and nearly half of US state Medicaid programs. Black Book ranked it first in its 2026 payer interoperability survey.
OnyxOS runs on Microsoft Azure and is sold in the Azure Marketplace. Onyx also sells a joint CMS-0057 product with Availity and acquired InteropX.
Smile Digital Health fits when a plan wants a broader FHIR data platform and digital HEDIS. 1upHealth fits when a plan wants a second bid from a vendor with a similar set of CMS APIs.
Competitor landscape
| Vendor | Overall | Ease of implementation |
|---|---|---|
| Particle Health | 7.4 | 7.0 |
| Kno2 | 7.3 | 7.3 |
| Zus Health | 7.2 | 7.0 |
| Metriport | 7.2 | 7.2 |
| Redox | 7.1 | 6.8 |
| Smile Digital Health | 7.1 | 6.6 |
| Onyx | 7.0 | 7.0 |
| Health Gorilla | 6.9 | 6.8 |
| 1upHealth | 6.7 | 6.5 |
Pricing
| Item | Detail |
|---|---|
| Model | Onyx sells its OnyxOS platform and services by contract. |
| What usually drives cost | For Onyx, cost depends on the APIs you need, member volume, Azure hosting, and the services hours in the contract. |
| What to ask before you buy | Ask Onyx which CMS-0057 APIs are in production for plans like yours, what ongoing monitoring costs, and how prior authorization connects to your UM vendor. |
| Note | Onyx offers a free one-week CMS-0057 readiness check. |
| Published pricing | Onyx does not publish a price list. |
Methodology
| Weight | Factor | What it measures |
|---|---|---|
| 35% | Customer outcomes | Whether buyers get measurable operational or clinical-workflow results after go-live |
| 30% | Product | Capability depth, reliability, and fit for the job the category buys |
| 20% | Implementation | How hard it is to stand up, integrate, train, and stabilize |
| 15% | Pricing clarity | Whether a buyer can model total cost without a mystery quote |
| Label | Meaning |
|---|---|
| Highly recommend | Strong outcomes and product with manageable caveats |
| Recommend | Solid fit for the right buyer; know the tradeoffs |
| Conditional | Only with a specific use case or heavy caveats |
| Not recommended | Avoid for most buyers in this category |
Read our full methodology for how we weight scores and assign recommend labels.