When Digital HEDIS was first introduced, Payers were required to complete a full year of parallel testing, which included running traditional and digital HEDIS measurements side by side, before submitting results to NCQA. This process was replaced in March 2026 with optional comparative testing.
According to NCQA: “Organizations assume the associated risk of not conducting comparative testing”.
This means the burden of validating digital results before submission now sits with the Payer. The HEDIS Compliance Audit still applies downstream, but nothing stands between a Payer’s digital output and its submission except the Payer’s own confidence in it.
This aligns with NCQA's broader move to validate data upstream, at the source, rather than only at the point of audit.
The burden of proof now sits with Payers, and their vendor evaluations have to go much deeper than the ability to calculate Digital HEDIS measures. Payers must also validate:
Accuracy across the Payer's own enterprise data environment, not just a vendor's test data
Consistency and reproducibility across different populations and programs
Explainability and traceability sufficient for a quality team to understand why and where variances occurred, and to hold up under audit
Scalability, as adoption and data complexity expands, and data volumes grow toward planetary scale
Operational readiness to act on results in impactful ways
Extensibility to custom, state, and jurisdictional measures on the same engine, without a new build or new fees each time
A vendor that cannot demonstrate the technology, the architecture, and a proven strategy for all six points above, transfers significant hidden risks to Payers.
Unlike the original parallel testing requirements, the measurement years for comparative testing do not have to be identical. Comparative tests can compare results across years allowing for more flexible and expedited testing.
Step 1: A Payer's members, claims, supplemental and clinical data is transformed and mapped to FHIR.
Step 2: The full target measure set is run against the measurement period data to produce population-level HEDIS Rates.
Step 3: The digital results are compared against the Payer’s traditional HEDIS results, measure by measure, with every discrepancy logged.
Step 4: The Payer’s HEDIS quality and operations team and the vendor’s Knowledge Engineering experts investigate the root causes of each discrepancy logged. Common root causes of discrepancies are:
Missing or incorrect supplemental data mappings
Data source differences between the traditional and digital pipelines
Value set version differences between the two engines
Edge cases in date boundary logic
Differences in continuous enrollment calculation
Discrepancies do not need to be eliminated. The deliverable is a documented explanation of why each one occurred.
Step 5: In-scope discrepancies are resolved and iterated upon. Measures are re-run on affected measures and the discrepancy log is updated accordingly.
Step 6: Payers decide on their own level of confidence and trust in the results. There are no thresholds and no NCQA approval at this stage.
The outcome of comparative testing is a documented, explained set of differences that gives the Payers a concrete base for the decision to submit.
HEDIS measure specifications are complex. In our experience with early-adopter Payer clients, we have traced most variances between digital and traditional to:
We see comparative testing as an exercise in validation, that establishes trust in a Payer’s digital measure outputs. It builds confidence with internal decision-making as technology, workflows and outputs are validated and explainable.
These are our real- world results from comparing traditional HEDIS results to OmniQ dQM - Measures for HEDIS results with early-innovator Payers.