There’s No Opting Out of This One: ASM Enters Year One in 2027
Cardiologists and spine/pain specialists in roughly a quarter of the country’s metro areas are about to face Medicare’s first mandatory specialist accountability model
Most of Medicare’s value-based care initiatives, including ACOs, MVPs, and even most CMS Innovation Center models, are voluntary. The Ambulatory Specialty Model (ASM) is not.
Finalized in the CY 2026 Physician Fee Schedule final rule, ASM is Medicare’s first mandatory, specialist-level accountability model, and January 1, 2027, is its first performance year.
The CY 2027 proposed rule (CMS-1848-P) is CMS’s last full rulemaking cycle to shape the model’s operational details before it goes live.
What it targets, and who’s in
ASM holds specialists accountable for the upstream management of two high-cost, high-prevalence conditions: congestive heart failure and low back pain.
Heart failure: general cardiology.
Low back pain: anesthesiology, pain management, interventional pain management, neurosurgery, orthopedic surgery, and physical medicine and rehabilitation.
Participation is triggered automatically, with no opt-out and no general hardship exemption, for clinicians who practice in one of the roughly 25% of core-based statistical areas (CBSAs) CMS selected nationally, and who have treated at least 20 Original Medicare patients with either condition over a trailing 12 months.
CMS released a preliminary list of 6,637 affected clinicians in February 2026. A final list, re-run against updated claims data, is coming ahead of the January 1 start date.
If you were on the preliminary list, plan as if you are in. If you were not, but practice in an affected specialty and area, check the final list carefully. You can still be added.
How performance gets scored
ASM uses four performance categories, split between individual and group-level assessment:
Quality, individual level: for example, blood pressure control in heart failure patients or functional status improvement in low back pain patients.
Cost, individual level: reductions in unnecessary or low-value care.
Care Improvement Activities, group level: clinical process improvement, patient engagement around lifestyle factors, and care coordination.
Promoting Interoperability, group level: technology that lets specialists share data with primary care.
What’s actually at stake financially
In Payment Year 1, adjustments to Medicare Part B claims range from -9% to +9%, scaling toward +/-12% in later years.
CMS designed the model to be budget-neutral in aggregate. Total positive adjustments for high performers cannot exceed total negative adjustments for low performers.
Performance years run from 2027 through 2031. Payment years lag roughly two years behind, running from 2029 through 2033.
What the CY 2027 rule can still change
The model’s core design, including who is in, the conditions, and the payment range, is locked in from the CY 2026 final rule.
What CY 2027 rulemaking can still shape:
Quality measure specifications for Performance Year 1.
The cadence and granularity of episode-level cost data feedback CMS provides to participants, including API access.
Edge-case clarifications, such as what happens to clinicians who join or leave a practice mid-year, and how the MIPS exemption ASM participants receive interacts with MVP registration.
Expansion signals. ASM was explicitly designed to extend to other conditions and specialties. Any preamble language or a new Request for Information about additional condition cohorts would be the earliest warning that gastroenterology, broader orthopedics, pulmonology, or other episode-heavy specialties could be next.
What affected practices should do now
Regardless of how the CY 2027 rulemaking cycle resolves, if you are a cardiologist or a spine/pain specialist practicing in an affected metro area, you need a 2027 operating plan now.
This rule only refines ASM at the margins. It does not change whether you are in.
Confirm your status against the final participant list as soon as CMS publishes it, and start building the care-coordination and data-sharing infrastructure the model expects.
Performance Year 1 scoring starts the same day the final rule’s other provisions take effect: January 1, 2027.
Chirpy Bird Inc helps specialty practices build an ASM readiness plan - from confirming participant status to standing up the care coordination workflows the model requires. Let's get you ready for Year One.
