If your group employs a cardiologist, an orthopedic spine surgeon, a physiatrist or a pain physician, check the final Ambulatory Specialty Model participant list this week. CMS published it in September. It names 5,556 specialists. Participation starts January 1, 2027, and it is mandatory.
ASM is a CMS Innovation Center payment model built on MIPS Value Pathways. It scores individual specialists who treat Medicare patients with one of two chronic conditions:
Performance is measured against peers treating the same condition. The adjustment runs from minus 9 percent to plus 9 percent in the first two performance years and widens to 12 percent in either direction by the last one. The model runs five performance years, 2027 through 2031.
Two mechanics matter more than the headline number.
The adjustment lands on your Part B professional services. CMS applies it to future Part B claims for covered professional services. It is not limited to the heart failure visits or the back pain visits. A specialist with a modest number of qualifying episodes still carries the adjustment across a much larger book of billing.
The money arrives late. The adjustment shows up on future claims, not the claims you file during the performance year. Trade press analysis puts 2027 performance on 2029 payment. A practice that learns it underperformed will be two years past the behavior that caused it.
CMS released a preliminary list in February. The final list is 16 percent shorter. The preliminary list was built on 2024 claims and the final list on 2025 claims, so physicians moved in both directions, not just out.
Participants are identified by a combination of Taxpayer Identification Number and NPI. So one physician billing under two group TINs can appear twice, and a physician who changed groups in 2025 can show up somewhere their current practice manager is not looking. Reporting on the final list counted twenty-three NPIs that appear more than once.
Run these in order. None of them needs a consultant. Plan on an afternoon.
Reporting on the list found that about 38 percent of named clinicians work in small practices, and among interventional pain physicians the figure is about 65 percent.
A health system has someone whose job is to read the Federal Register. A four-physician spine group does not. The penalty for missing the notice is the same for both.
That is the operational problem underneath the policy one. The large system will find its names in an hour. The small group may find out in 2029, from a payment line that went down.
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The rules are not frozen. CMS proposed changes to ASM in the CY 2027 Physician Fee Schedule proposed rule, and MGMA expects the final rule on or about November 1. The participant list is final. Some of the terms around it may not be.
That is not a reason to wait. The five checks above do not depend on the final rule. They depend on knowing whose name is on the list, and you can know that this week.
January 1 is 94 days from the morning this was published. The list does not get longer between now and then. It just gets harder to act on.
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Dr. Sarah Matt is a surgery-trained physician-executive currently practicing internal medicine (charity care). She advises health systems and digital health companies on clinical AI implementation, vendor contracting and operational strategy.
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