CMS names final 2027 mandatory Ambulatory Specialty Model participants and reporting steps

What happened

The September 17 MLN Connects newsletter announced the final participant list for the mandatory Ambulatory Specialty Model’s 2027 performance year. CMS directs specialists who frequently treat Original Medicare patients for outpatient low back pain or heart failure to check whether they were selected. Selection carries all applicable model requirements, including required measure reporting and attestations. The newsletter’s announcement of a final list is a participation and readiness event; it does not make every clinician who treats either condition a participant without checking the actual selection.

CMS states that participants’ future Medicare Part B payments will be adjusted based on performance on reported measures and activities. That links data and attestation readiness to later payment consequences while preserving the distinction between a performance year and the future payment adjustment. The newsletter also offered a September 30 office hour and linked the model’s participant, model and FAQ pages. As of October 4, that event date has passed, but selected organizations still need to identify applicable specifications and reporting responsibilities before the 2027 performance year. The newsletter itself does not list every individual reporting deadline.

Why it matters

Selected specialists need clear ownership of measure data, attestations and financial modeling before performance begins.

Implementation playbook

1. Confirm whether the organization appears on the final participant list. Clinical Operations · Due 2026-10-02
2. Inventory reporting and attestation requirements. Quality · Due 2026-10-16
3. Test measure and payment source data. IT · Due 2026-11-13

Sources

• MLN Connects Newsletter, September 17, 2026Official · Centers for Medicare and Medicaid Services · 2026-09-17 · Source review 2026-09-20