CMS gave ACOs several wins, but the payment squeeze is still unresolved
The final 2027 Medicare Physician Fee Schedule gave accountable care organizations a mix of relief and renewed pressure. On one hand, CMS lowered the conversion factor by 1.83% for clinicians in qualifying advanced alternative payment models and by 2.31% for everyone else, a deeper cut than the agency had proposed in July. On the other, the rule added benchmark guardrails, replaced the G2211 add-on with modifiers B1 and B2 for more complex ACO visits, and opened the door for ACOs to reduce or eliminate patient cost sharing for Part B services beginning April 1, 2027.
Aisha Pittman, M.P.H., senior vice president of government affairs at the National Association of ACOs, framed the rule as a partial victory with a large unfinished bill attached. The practical benefit of the new policies is easy to see at the practice level: stronger ACO benchmark rules can make shared-savings targets less punitive, while cost-sharing flexibility can help clinicians keep patients engaged in chronic care and transitional care management. Yet the deeper physician payment cuts still threaten the basic arithmetic of value-based care. An ACO cannot absorb more financial risk for longer stretches if the underlying fee schedule continues to erode cash flow.
Benchmark math still shapes whether savings look real or artificial
The benchmark issue sits at the center of the ACO argument. Pittman described the accountable care prospective trend as the key provision for NAACOS members because early benchmark behavior had worked against groups that already lowered spending. When targets reset repeatedly, successful ACOs can be measured against a moving baseline that rewards new entrants more than long-tenured participants. In effect, the better a group performs over time, the harder it can become to show additional savings.
CMS kept the trend within 1% below to 1.5% above health care inflation, a constraint that matters because it limits how far benchmarks can drift away from real-world spending growth. For organizations that have spent years reducing unnecessary utilization, improving coordination, and tightening post-acute care decisions, that guardrail creates a more credible measurement frame. It also reflects a basic tension inside shared savings: if the target becomes too aggressive after years of cost control, the model starts punishing the very efficiency it was designed to promote.
One sentence captures the problem better than any policy memo could: successful ACOs can end up paying for their own performance.
Congress still holds the lever on physician payment and APM incentives
Pittman argued that Congress has to do more than CMS can do through regulation. NAACOS wants lawmakers to reverse the 2027 cut, build an inflation update into physician payment, and extend advanced APM incentive payments for another year. Those requests are not abstract budget politics. They are an attempt to preserve the front-end margin that allows practices to invest in care managers, analytics, and workflow redesign before downside risk begins.
Pittman’s point about timing inside accountable care is blunt: practices usually need three to five years to see results. That lag reflects the biology of practice transformation as much as the economics of it. Patients do not change utilization patterns overnight, referral relationships take time to stabilize, and quality gains often arrive before savings do. If payment falls too quickly at the start, the model can collapse before the organizational changes have a chance to mature.
She also wants primary care capitation or hybrid payment brought into the permanent Medicare Shared Savings Program. CMS has already tested those approaches in ACO REACH and plans them for the LEAD model. The policy logic is straightforward: capitation smooths cash flow, reduces dependence on visit volume, and gives practices a more predictable base for population management. In a system built around longitudinal coordination, that kind of payment design can be more compatible with preventive and chronic disease care than pure fee-for-service billing.
Administrative burden is still draining ACO operations
Pittman also pointed to changes in beneficiary notification requirements as a meaningful operational win. ACOs spend considerable staff time on notices, documentation, and reporting workflows, and each administrative simplification frees people to focus on outreach, attribution, and care coordination. That matters because ACO performance depends on operational discipline as much as on clinical intent. Every hour that nurses, coordinators, and practice managers spend chasing paperwork is an hour not spent reducing avoidable admissions or closing care gaps.
The quality reporting side remains tangled. Pittman said keeping existing reporting options matters because ACOs are still struggling to extract electronic quality data from hundreds of practices, even as CMS works toward a 2030 goal for digital quality measures. The challenge is not simply technical. Primary care groups and specialists often sit on different EHR platforms, data definitions vary, and aggregation across a large network can lag behind the pace of policy change. A digital future is useful only if the plumbing works before the deadline arrives.
The end of MIPS changes less for many ACO clinicians than it would for solo fee-for-service practices, but the transition still signals a broader shift in how Medicare wants to evaluate performance. Pittman said MIPS Value Pathways have not fully solved quality measurement for physicians. For ACOs, the problem is not whether quality should be measured. It is whether the measurement system can keep pace with care delivered across dispersed sites, varied contracts, and increasingly hybrid payment structures.
Cost sharing, modifiers, and the bedside economics of complex care
Two other parts of the rule carry immediate clinical meaning. First, CMS kept a higher complexity payment structure through the replacement of G2211 with B1 and B2, which Pittman said adds an incentive Congress never required. For ACO clinicians, that is a recognition that complex longitudinal care requires more time, more coordination, and more cognitive work than a routine office visit.
Second, beginning April 1, 2027, ACOs will be able to reduce or eliminate patient cost sharing for Part B services such as chronic care management and transitional care management. Medicare will still pay its full share, while the ACO absorbs the patient portion. That arrangement could improve uptake of services that often make the difference between a stable outpatient course and a preventable hospitalization. Lower out-of-pocket costs can remove a small but important barrier to follow-up, especially for patients who need frequent touchpoints after discharge or during chronic disease flares.
Still, the model leaves ACOs carrying more financial and operational responsibility while physician payment remains under strain. The final rule gives value-based care organizations a few sharper tools, but the deeper fix remains legislative. Congress controls whether those tools are enough to keep the system from undercutting the groups that have already shown they can bend cost curves.