CMS Has Published the Final Ambulatory Specialty Model Participant List. Specialists Should Check It Before Jan. 1.
More than 5,500 cardiologists and back pain specialists are on the final list for Medicare's mandatory Ambulatory Specialty Model. Performance year one starts Jan. 1, 2027, and it sets Part B adjustments of up to 9 percent either way in 2029.
The Centers for Medicare and Medicaid Services has released the final participant list for the Ambulatory Specialty Model, the American College of Cardiology reported on Sept. 15. The list is posted on CMS's data site and can be searched by name, organization, state and National Provider Identifier. The model is mandatory, and its first performance year begins Jan. 1, 2027.
The ACC counted more than 5,550 clinicians on the final list, 2,215 of them in the heart failure cohort, and said CMS added no one who was not on the preliminary list released in February. Cardiology has drawn most of the attention, but the model covers two conditions. According to the CMS model fact sheet, the heart failure cohort is cardiology, and the low back pain cohort covers anesthesiology, pain management, interventional pain management, neurosurgery, orthopedic surgery and physical medicine and rehabilitation.
Who is in the model
Per the fact sheet, participants practice in selected core-based statistical areas or metropolitan divisions and historically treated at least 20 Original Medicare patients with heart failure or 20 with low back pain over 12 months. CMS finalized the model in the calendar year 2026 physician fee schedule final rule, which limited the heart failure cohort to the cardiology specialty code and left out subspecialty codes such as interventional cardiology, electrophysiology and advanced heart failure and transplant cardiology.
The final list does not fully match that design. The ACC noted that numerous physicians who practice electrophysiology, interventional cardiology or advanced heart failure remain on it. CMS has proposed an exception for heart failure participants who redesignate their specialty, which is not yet final.
What participants are measured on
The fact sheet lists four performance categories: quality, cost, improvement activities and promoting interoperability. Quality examples include blood pressure control in heart failure and functional status in low back pain. Physicians are assessed individually on quality and cost, and at the group level on improvement activities and interoperability.
Under the 2026 final rule, quality and cost each count for 50 percent of the final score. Improvement activities and interoperability do not add points; poor performance or non-reporting can subtract up to 20 and 10 points, respectively. Participants in practices of 2 to 15 clinicians receive 10 added points, solo practitioners 15, and those treating many medically complex patients up to 10. A participant who does not meet the quality data submission requirement cannot do better than the maximum negative adjustment.
Final scores set a positive, neutral or negative adjustment to all of a participant's Medicare Part B professional claims in the payment year, not only those for the targeted condition. The fact sheet says every participant carries risk, that the range is -9 percent to +9 percent in the first payment year, and that total positive adjustments cannot exceed total negative ones. The final rule sets the maximum at 9 percent for the 2029 and 2030 payment years, rising to as much as 12 percent later in the model.
Nothing changes on a claim in 2027. What is scored in 2027 sets the size of the Part B adjustment in 2029.
The criticism, and what could still change
The ACC submitted comments on Sept. 10 on the calendar year 2027 fee schedule proposed rule. It urged CMS to reconsider the model's structure, including individual attribution, citing limited data transparency, and recommended that at least the first year be a no-risk educational and testing period, which it said would require postponing the Jan. 1, 2027 start. It said member feedback showed significant uncertainty and low confidence in controlling costs.
The 2027 proposed rule does make operational changes to the model. They include broader exceptions for taxpayer identification number changes, the specialty redesignation exception for heart failure participants, an option for CMS to terminate participants in certain circumstances, a 5-point final-score adjustment for qualifying rural participants and a 5-point quality bonus for submitting patient-reported outcome data when CMS opens that option. These are proposals until CMS issues the 2027 final rule.
What practices should do now
Search the final list for every physician in the group by National Provider Identifier and compare it with the February preliminary list. For anyone on it, confirm the specialty and taxpayer identification number CMS has on file. Under the 2026 final rule, a participant's payment adjustment follows the physician's NPI to a new TIN, so recruits and departures deserve a second look.
Ask your EHR vendor or registry now whether it can support individual-level quality reporting for 2027, and name who in the group owns improvement activities and interoperability submissions. Groups that already track their MIPS feedback can reuse that workflow. Questions for CMS go to the model team at AmbulatorySpecialtyModel@cms.hhs.gov, the address listed on the fact sheet.
Reported, fact-checked and edited by The Script Pad's editorial staff.
This article is for professional education and does not replace clinical judgment. Treatment decisions should be based on the individual patient and current guidelines.
