The Centers for Medicare and Medicaid Services (CMS) is evaluating the feasibility of automatically enrolling Medicare beneficiaries into Medicare Advantage (MA) plans or accountable care organizations (ACOs), according to statements made by Chris Klomp, the Trump administration’s Medicare director, on March 20, 2026. The proposal, which aligns with recommendations outlined in the conservative Project 2025 policy blueprint, would represent a substantial departure from longstanding Medicare enrollment practices.

Under current federal policy, beneficiaries who do not actively select a coverage arrangement default into traditional fee-for-service (FFS) Medicare. The proposed model would invert that default, placing newly eligible or non-electing beneficiaries into either a private MA plan or an ACO, such as those participating in the Medicare Shared Savings Program (MSSP). Individuals would retain the ability to opt into an alternative arrangement, including traditional Medicare.

Klomp, speaking at a public forum, characterized the prospective change as a matter of structural efficiency and care continuity. He argued that default enrollment into FFS Medicare fails to establish the longitudinal patient-provider relationships that support coordinated, value-based care delivery.

“Would either of those, in my view, be superior to a default enrollment into a fee-for-service arrangement, where there’s not this long-term, secular relationship between the beneficiary, the patient, and their provider? Yes,” Klomp stated.

CMS has not announced a formal rulemaking process or timeline for the proposal. Klomp’s remarks indicate that the agency is at a preliminary stage, assessing whether such models would be operationally viable before any policy action is taken.

Background: The Current Medicare Enrollment Framework

Medicare serves approximately 67 million beneficiaries in the United States. Historically, the program’s default coverage pathway has been traditional FFS Medicare, in which the federal government pays directly for covered services rendered by participating providers. Beneficiaries enrolled in FFS Medicare may access any provider who accepts Medicare, providing broad freedom of provider selection.

MA, established under the Medicare Modernization Act of 2003 and governed under Medicare Part C, allows private insurers to administer Medicare benefits under contract with CMS. MA plans are required to cover all services included in traditional Medicare Parts A and B, and most plans offer supplemental benefits such as dental, vision, and hearing coverage not available under FFS Medicare. In exchange for these benefits, enrollees typically operate within defined provider networks and may face prior authorization requirements for certain services.

As of early 2026, MA enrollment accounts for more than half of all Medicare beneficiaries, reflecting a steady multi-year trend of growth in the private plan sector. Advocates of MA point to its integrated care models and supplemental benefits as advantages over traditional FFS Medicare. Critics, including a number of patient advocacy organizations and some clinical researchers, have raised concerns about coverage denials, prior authorization delays, and the financial pressures that narrow networks may place on certain patient populations, particularly those in rural or underserved communities.

ACOs represent a distinct category of value-based care arrangement. Under the MSSP and related models, ACOs are groups of physicians, hospitals, and other health care providers who coordinate care for attributed Medicare beneficiaries. Unlike MA plans, ACOs operate within the traditional FFS Medicare framework while accepting shared savings or shared risk arrangements based on their ability to reduce costs relative to benchmarks. Beneficiaries attributed to ACOs retain full freedom of provider choice and are not formally enrolled in a separate plan structure.

Project 2025 and the Policy Context

The proposal under consideration by CMS echoes recommendations contained within Project 2025, a policy document produced by the Heritage Foundation and affiliated conservative organizations prior to the 2024 presidential election. The document, which offered a comprehensive administrative blueprint for a conservative administration, included provisions advocating for structural reforms to Medicare, among them the concept of redirecting default enrollment away from FFS Medicare toward private or value-based alternatives.

The inclusion of MA default enrollment in Project 2025 generated considerable attention and controversy during the 2024 campaign cycle and continued to draw scrutiny as the Trump administration moved into its second term. Opponents of the proposal argued that it could limit beneficiary choice, particularly for individuals who are unfamiliar with the Medicare enrollment process or who face language and literacy barriers. Supporters contended that the change would accelerate the transition to value-based care models and reduce long-term Medicare expenditure growth.

Klomp’s remarks confirm that the administration is actively pursuing at least the preliminary examination of this concept, though no legislative or regulatory action has been formally announced.

Clinical and Policy Implications

The question of whether default enrollment into MA or ACO arrangements would produce superior clinical outcomes relative to traditional FFS Medicare is one that the existing medical literature has not resolved with consistency.

Several analyses have identified MA enrollees as demonstrating favorable outcomes on certain quality metrics, including rates of preventive screening, management of chronic conditions, and hospital readmission rates. Proponents attribute these results to the care coordination and disease management programs that MA plans are incentivized to operate. Other research has identified selection effects, noting that MA enrollment has historically been higher among healthier, younger, and more affluent Medicare beneficiaries, which may confound outcome comparisons with the FFS population.

Research examining ACO performance under the MSSP has produced mixed findings. Some ACOs, particularly those with longer program participation and greater provider integration, have demonstrated statistically significant reductions in Medicare expenditures alongside stable or improved quality scores. Others have struggled to generate consistent savings or to sustain quality benchmarks across measurement periods. The heterogeneity of ACO performance has led some health policy researchers to caution against broad generalizations about the MSSP’s effectiveness as a default care arrangement.

A central clinical concern raised by physicians and patient advocates with respect to MA default enrollment is the issue of prior authorization. MA plans are permitted by regulation to require prior authorization for a range of services, and the volume and denial rates associated with prior authorization requests have drawn scrutiny from Congress, CMS, and independent oversight bodies. The American Medical Association and several specialty societies have consistently reported that prior authorization requirements delay or disrupt care, with particular consequences for patients managing serious or complex conditions.

The implications of auto-enrollment for rural Medicare beneficiaries merit specific consideration. MA plan participation in rural markets has historically been more limited than in metropolitan areas, and the plans that do operate in rural geographies may offer narrower networks. A default enrollment model that assigns beneficiaries to MA plans in markets with limited plan competition or provider network depth could constrain access to subspecialty care in ways that would not apply in urban settings.

Conversely, proponents of the ACO default enrollment pathway argue that this option preserves FFS Medicare’s structural openness while layering care coordination infrastructure onto the beneficiary’s care experience. Under ACO attribution, beneficiaries would retain the ability to see any Medicare-participating provider without referral or network restriction, which addresses some of the access-related objections raised against MA default enrollment.

Regulatory Pathway and Practical Considerations

Any formal implementation of auto-enrollment would require either congressional authorization or CMS rulemaking under existing statutory authority, depending on the legal mechanism pursued. The scope of the proposed change would likely necessitate a formal rulemaking process involving a notice-and-comment period, which would provide an opportunity for stakeholders including beneficiary advocacy organizations, health plans, provider associations, and state Medicaid agencies to submit formal input.

Questions of beneficiary notification, opt-out procedures, and special enrollment protections would require resolution before any auto-enrollment model could be operationalized at scale. Individuals who are dually eligible for Medicare and Medicaid present a particular administrative complexity, given that their coverage arrangements intersect with both federal and state program rules.

The feasibility assessment that Klomp described would presumably need to address plan availability across all Medicare service areas, the infrastructure required to match beneficiaries to plans or ACOs in a default assignment process, and the mechanisms by which beneficiaries would be informed of their enrollment status and their options for changing coverage.

CMS has administered limited auto-enrollment mechanisms in the past in specific contexts, including the assignment of low-income subsidy (LIS) beneficiaries to Part D prescription drug plans when they do not make an active selection. That precedent, while narrower in scope than the proposal under discussion, demonstrates that CMS possesses at least some operational experience with default plan assignment frameworks.

Stakeholder Response

The proposal has not yet advanced to a stage at which formal public comment has been solicited, but advocacy organizations representing Medicare beneficiaries have expressed concern about the direction of the discussion. Groups focused on patient access and consumer protection have historically opposed auto-enrollment proposals on the grounds that beneficiaries may find it difficult to navigate the opt-out process, particularly those with cognitive impairment, limited English proficiency, or limited familiarity with insurance plan structures.

Health plan industry representatives, by contrast, have generally supported policies that expand MA enrollment, citing the program’s ability to deliver coordinated care and supplemental benefits within a defined budget structure.

The medical community’s response is likely to track closely with the specific design of any proposal that emerges from CMS’s feasibility review. Physicians who practice within value-based care arrangements or integrated health systems may view expanded ACO or MA enrollment favorably. Those in solo or small-group practice settings with limited MA contracting may raise