CMS opens CY 2027 Medicare Advantage provider-directory preview and sets September 18 attestation deadline

What happened

CMS's September 2, 2026 provider-directory memo opened HPMS preview September 8 and explicitly kept it available on an ongoing basis, with feedback until further notice. The September 4 final technical guide, version 1.5, set September 18 as both the CY 2027 attestation deadline and target for production-ready data, ahead of the planned October 1 release. As of October 4, those dated milestones had passed; the sources do not establish that a particular organization attested or that the ongoing preview closed. This article's closed milestone concerns the September deadline, not continuing directory maintenance.

The guide covers individual MA plans, including local and regional coordinated-care plans and network-based MSA/PFFS plans. It requires public machine-readable or FHIR-based JSON, accurate provider-to-contract/plan/segment links and annual attestation by an authorized CEO, CFO or COO. Plans must update information within 30 days of learning of a change. Daily validation distinguishes fatal submission failures, record-level errors and informational warnings; fatal submissions are withheld, while warnings can remain displayed. Technical validation does not verify underlying data accuracy. The preview helps test provider and facility NPIs, but an organization remains responsible for accuracy, public access and unresolved validation findings.

Why it matters

Ongoing data accuracy and technical validity remain separate from the expired attestation deadline. A technically accepted file can still contain inaccurate network information.

Implementation playbook

1. Confirm HPMS preview access for every affected MA contract and test representative practitioner and facility NPIs across all plan and segment combinations. Managed Care · Due 2026-09-11
2. Validate each public index and constituent JSON or FHIR file from an external network, including syntax, authentication-free access, compression, HTTP headers, file limits and contract-plan-segment relationships. IT · Due 2026-09-14
3. Review HPMS validation results and correct fatal errors, missing plan segments and stale provider data before the production target. Provider Enrollment · Due 2026-09-16
4. Route the final evidence to an authorized CEO, CFO or COO and complete the CY 2027 provider-directory attestation in HPMS. Executive Leadership · Due 2026-09-18

Related coverage

The annual officer attestation and 30-day update rule are compliance controls for affected Medicare Advantage organizations. Compliance Sweep →

Sources

• Contract Year 2027 Provider Directory Plan PreviewOfficial · Centers for Medicare & Medicaid Services · 2026-09-02 · Source review 2026-09-10
• CMS HPMS Memos for WK 1 September 1-4, 2026 bundle, including the September 4 technical guideOfficial · Centers for Medicare & Medicaid Services · 2026-09-04 · Source review 2026-09-10
• CMS HPMS Memos for WK 1 September 1-4, 2026 archive pageOfficial · Centers for Medicare & Medicaid Services · 2026-09-04 · Source review 2026-09-10