CMS outlines mandatory Ambulatory Specialty Model for selected specialists starting Jan. 1, 2027

The Centers for Medicare & Medicaid Services’ Center for Medicare and Medicaid Innovation on an ASM office hour said the Ambulatory Specialty Model is a mandatory alternative payment model for selected specialists that will start Jan. 1, 2027, and run five performance years through 2031.

“ASM is a mandatory model,” said Ben Puccio, ASM Model Lead, who explained the model will test whether performance‑based payment adjustments for specialists paid under Original Medicare can improve care for patients with common chronic conditions. CMS named two clinical cohorts: cardiology specialists for a heart failure cohort and a low back pain cohort including anesthesiology, interventional pain, neurosurgery, orthopedic surgery, pain management, and physical medicine and rehabilitation.

CMS will identify participants at the level of a TIN–NPI combination. A clinician is eligible for a performance year if the TIN–NPI meets four conditions: the clinician bills under the Medicare physician fee schedule; has one of the selected specialty types; has 20 or more attributed episodes from either the heart failure or low back pain episode‑based cost measure (EBCM); and practices in an ASM‑selected mandatory geographic area (a CBSA or metropolitan division).

Eligibility is assessed using administrative data from two calendar years before the performance year. “Our final determinations for the ASM participants for the 2027 performance year will use data from calendar year 2025,” Puccio said, noting that CMS released a preliminary 2027 participant list in February 2026 based on 2024 data and will reassess with 2025 data in late summer 2026.

CMS said it expects few additions to the preliminary list but that some clinicians may be removed because of changes in service location, specialty, or episode volumes. If an NPI is associated with multiple TINs, CMS treats each TIN–NPI combination as a separate participant, requiring separate reporting and performance assessments for each.

CMS also described how service location is determined: service‑location ZIP codes from the claims that construct each EBCM episode are mapped to a single CBSA or metropolitan division, and the participant’s service location is the most common CBSA across their attributed episodes. Puccio cautioned that the service location CMS determines for a participant may differ from the organization state listed on the public dataset and said CMS is checking for such discrepancies before the final list is posted.

The ASM team said it will notify preliminary participants by email and post the participant dataset on data.cms.gov; CMS cannot publish TINs publicly because of privacy rules. Puccio advised clinicians to complete the ASM participant contact information form and monitor email (including junk folders) so they receive portal registration information when the participant portal opens, which CMS expects in late summer 2026.

Next steps: CMS will finalize the 2027 participant list after reassessment using 2025 data, publish guidance on how to notify CMS of organizational changes not reflected on the final list, and post supporting materials (webcasts and slides) on the ASM website.

The office hour concluded with CMS posting resource links in the chat and asking attendees to direct case‑specific questions to ambulatorypecialtymodel@cms.hhs.gov.