CMS Has Finalized the 2027 Ambulatory Specialty Model List. What Selected Practices Need to Know Before January 1

Updated September 29, 2026

Why this is now an immediate practice issue

CMS has released the final participant list for the 2027 Ambulatory Specialty Model (ASM) performance year. For physicians selected by CMS, the model begins January 1, 2027, and participation is mandatory for the performance years in which they meet the model’s eligibility criteria.

For practice leadership, the first question is no longer whether ASM may eventually apply. It is whether a specific physician, identified by the physician’s Taxpayer Identification Number (TIN) and National Provider Identifier (NPI) combination, appears in the final CMS participant dataset - and, if so, whether the practice is ready for the performance and reporting requirements that begin in 2027.

ASM is a mandatory CMS Innovation Center model with five performance years, from January 1, 2027, through December 31, 2031. CMS reassesses eligibility annually, so participation status can change from one performance year to another.

Who can be selected

ASM has two cohorts tied to chronic conditions. The heart failure cohort includes physicians whose specialty type is cardiology. The low back pain cohort includes physicians whose specialty type is anesthesiology, interventional pain management, neurosurgery, orthopedic surgery, pain management, or physical medicine and rehabilitation.

Specialty alone does not determine participation. CMS identifies individual physicians using a unique TIN/NPI combination. To be selected, a physician must bill under the Medicare Physician Fee Schedule, have an included specialty type, be attributed 20 or more episodes under the relevant episode-based cost measure, and practice in a selected mandatory geographic area.

For the 2027 performance year, CMS used 2025 data to evaluate eligibility. CMS will reassess the criteria annually.

The final list matters more than a practice-wide assumption

A practice should not assume that every physician in an affected specialty - or every physician in the same group - has the same ASM status. Eligibility depends on the individual physician’s specialty, attributed episodes, geography, and TIN/NPI combination.

CMS announced the final 2027 participant list in September 2026 and directed specialists who frequently treat Original Medicare beneficiaries with heart failure or low back pain in outpatient settings to check whether they were selected.

That makes the final CMS participant dataset the appropriate starting point. Before changing workflows or assigning reporting responsibilities, practice leaders should confirm exactly which physicians are on the final list.

What begins with the 2027 performance year

ASM evaluates participants across four performance categories: quality, cost, improvement activities, and Promoting Interoperability. The framework borrows elements that may be familiar to practices that have worked with MIPS Value Pathways, but CMS states that ASM has different requirements, scoring, and payment-adjustment methodologies.

For performance years in which a physician is required to participate in ASM, the physician is exempt from MIPS requirements, subject to limited exceptions. That does not erase 2026 obligations: physicians who are MIPS-eligible for calendar year 2026 should continue their 2026 MIPS reporting because ASM does not begin until January 1, 2027.

For the 2027 ASM performance year, required quality data, improvement-activity attestations, and Promoting Interoperability data and attestations are due by March 31, 2028. CMS plans to use the Quality Payment Program portal for ASM reporting and says additional reporting guidance will be released.

The payment effect comes later - but the performance period starts first

ASM separates the performance year from the later payment year. CMS states that the final score earned for the 2027 ASM performance year will determine the ASM payment adjustment applied to Medicare Part B covered professional-service payments during the 2029 payment year.

That two-year lag can make the model appear less urgent than it is. A practice may not see an ASM payment adjustment on 2027 claims, but the performance that determines the 2029 adjustment is being measured during 2027.

CMS states that ASM payment adjustments range from -9% to +9% in the first two payment years, 2029 and 2030, and increase in later years, reaching a range of -12% to +12% by the end of the model.

For practice leadership, ASM is therefore not primarily a 2027 claim-edit change. It is a performance, reporting, care-coordination, interoperability, and data-management issue that can later change Medicare Part B payments for a selected physician’s covered professional services.

What ASM does not mean

ASM does not mean every physician in an affected specialty is automatically included. Participation depends on the full CMS eligibility criteria and the physician’s TIN/NPI combination in the participant dataset.

It also does not mean a selected physician will immediately see a 9% increase or decrease on 2027 claims. The 2027 performance year feeds a later payment adjustment; CMS ties 2027 performance to the 2029 payment year.

And ASM should not be generalized into a rule for every payer. The model applies to selected physicians and Medicare Part B covered professional services. Commercial plans, Medicaid, and Medicare Advantage operate under separate payment arrangements and requirements.

Why this belongs on the revenue-cycle radar

Revenue-cycle teams are accustomed to changes that affect a claim immediately: coding, eligibility, authorization, submission rules, denials, or payer edits. ASM works differently. Its payment effect is downstream, while the inputs are created earlier through performance, cost, care coordination, interoperability, and required reporting.

That changes the management question. A practice should not wait for a future payment adjustment to discover that a physician was being measured under a mandatory model. By then, the performance year that produced the adjustment will already be over.

The operational risk is broader than a rejected claim. It is failing to recognize that a selected physician is now subject to a mandatory specialty payment model with its own performance framework, reporting requirements, and future Part B payment consequences.

What practice leaders should verify before January 1

First, check the final CMS participant dataset using the physician’s exact TIN/NPI combination. Do not rely only on specialty, location, or a preliminary list from earlier in 2026.

Second, identify which ASM cohort applies and assign clear ownership for readiness. The model reaches beyond billing because quality, cost, improvement activities, interoperability, and collaboration can all affect performance.

Third, map the reporting infrastructure the practice will rely on in 2027. CMS readiness materials tell participants to review required measures, determine how they will report, ensure their infrastructure is equipped for reporting, and prepare relevant staff for workflow or reporting adjustments.

Fourth, keep 2026 and 2027 obligations separate. A physician who is MIPS-eligible in 2026 should continue 2026 MIPS reporting even if that physician is a final ASM participant for 2027.

Finally, use current CMS ASM resources rather than older summaries. CMS has continued to publish onboarding materials, FAQs, participant resources, and portal guidance as implementation approaches.

The bigger lesson for independent and small specialty practices

A mandatory payment model can be easy to underestimate when the payment adjustment arrives two years after the performance period. For a small practice with a selected physician, however, the more important near-term date is January 1, 2027 - the beginning of the first performance year.

The goal is not to turn a physician owner or practice manager into a quality-reporting specialist. It is to make sure the organization knows who is in the model, who owns readiness, which data and attestations must be reported, whether the reporting infrastructure is prepared, and how leadership will monitor performance during the year.

CMS has moved ASM from a future policy to a final participant list. For practices with selected physicians, readiness is now an operational responsibility.