HEDIS® Timeline

The HEDIS Compliance Audit™ is conducted over a nine-month period beginning in October and ending in June. Although the events are described sequentially, the audit tasks are not necessarily performed in that order. We have the flexibility to conduct each step in accordance with a mutually agreed upon approach. A monthly narrative breakdown of the essential audit steps can be found below. A sample timeline following the narrative shows one possible schedule variation. Flexibility is key, as some clients prefer site visits in January, while others prefer late April.

October – December

Attest hosts a client workshop in October each year. Attest staff, health plan representatives, and HEDIS® vendors convene to discuss the upcoming HEDIS Compliance Audit™. Attest provides each health plan with a Communications Manual designed to provide an overview of key steps and reference guide for procedural questions. Sometime between late-November through early-December, Attest hosts a Kick Off call with each health plan to introduce the audit as well as to introduce the Attest Audit Team (this usually consists of 2-3 auditors) to the health plan.

At the start of November, the auditor will select the Core Set of measures for source code review. In December, the health plan will submit the source code for any non-certified hybrid measures for auditor approval. Before the end of the year, health plans will complete and submit the Roadmap to their Audit Team for review.


In early January, the health plan will receive auditor feedback in an issue log based on the Roadmap review. Additionally, your Audit Team will also approve the CAHPS survey programs and sample frame.


During February, the health plan will be finishing supplemental data source (SDS) collection and source code submission in order to meet the March deadlines. Additionally, site visits begin in February and continue throughout late April. Health plans submit requested documentation (transaction system screenshots, etc.) and a site agenda to their Audit Team at least 7 days prior to the site visit. The Audit team will use this time to review all documentation prior to arrival. The plan will receive a post-site letter and Issue Log within 7 days after the site visit.


Collection of Nonstandard and Member-reported supplemental data must be completed by March 1, when the health plan submits a comprehensive list of SDS events to their Audit Team. Based on this list, Attest will select a sample of the Member-reported and Nonstandard SDS data within the following week. The health plan provides the proof-of-service documentation for each sample for primary source verification. Auditor review and approval for Standard, Member-reported, and Nonstandard SDS must be completed by the last business day of March.

Lastly, all source code for the Core Set of measures must be approved by the end of March. The administrative source code is due to the Audit Team during the first week of March, and the health plan resolves any source code related issues before the end of the month.


The audit will be about 75% finished by the end of April, and the health plan submits preliminary administrative rates for benchmarking and review of all measures. All onsite visits must be completed by April 30.


The health plan will complete abstracting and submit a list of hybrid hits, including frozen hybrid counts by May 9. Based on the list of hybrid hits, the auditor will select the validation sample and send the list back to the health plan. On or before May 15, medical records must be submitted for MRRV. Validation results will be reported to the health plan within a few days after submission.
Other items due in May include the health plan’s IDSS (post-refresh), and SDS impact reports. A fully populated IDSS for all submissions is due by May 24 and the patient level detail (PLD) file.

The plan lock deadline for all submissions in IDSS is by June 1. This data must be final and the lock can only be removed for correct data. Most importantly, final HEDIS® rates are due to NCQA no later than June 15, 2018. After rates are finalized in June, the Audit Team will issue a Draft Audit Report to the health plan. The health plan submits comments before a Final Audit Report will be sent to the health plan and NCQA by the end of the month.

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Attest Health Care Advisors is an NCQA-licensed organization authorized to conduct HEDIS® audits. Only an NCQA-licensed organization is authorized to conduct HEDIS Compliance Audits™.