New Bipartisan Bill Seeks To Expand Medicare ACO Assignment Rules

U.S. Senators Sheldon Whitehouse (D-RI) and John Barrasso (R-WY) have introduced bipartisan legislation to expand access to high-quality, coordinated health care. The ACO Assignment Improvement Act aims to increase participation in Medicare's coordinated-care programs by ensuring that care provided by nurse practitioners, physician assistants, and clinical nurse specialists counts toward a patient's eligibility for an Accountable Care Organization (ACO). This update will help Medicare beneficiaries receive more seamless, integrated, and high-quality care.

ACOs are networks of hospitals, physicians, and other health care providers that work together to deliver coordinated care. They have proven effective in improving care quality and reducing costs. According to the Centers for Medicare & Medicaid Services, ACOs saved Medicare approximately $2.4 billion in 2024—the program's eighth consecutive year of net savings and its highest savings to date—by focusing on high-quality, coordinated care.

For many Americans, particularly those in rural communities, their primary care provider is often a nurse practitioner or physician assistant. However, current Medicare rules typically assign patients to an ACO only if they receive care from a physician. The ACO Assignment Improvement Act updates this policy to allow patients who rely on nurse practitioners, physician assistants, and clinical nurse specialists to participate in ACOs. This change reinforces longstanding patient-provider relationships and expands access to the coordinated care that ACOs are designed to deliver. A companion bill (HR4773) has also been introduced in the House by Representatives Adrian Smith (R-NE) and Suzan DelBene (D-WA).

At present, the legislation faces limited momentum. It lacks a substantial list of cosponsors and has not been included in broader Medicare or health care negotiations. Without a larger legislative vehicle or committee-driven push, the bill is unlikely to advance independently this Congress. However, the policy aligns with bipartisan priorities around care delivery reform, rural access, and strengthening primary care, so it could reemerge as part of a future Medicare extenders package, value-based care legislation, or CMS regulatory updates. We will continue monitoring for new cosponsors, stakeholder endorsements, and opportunities for the bill to be incorporated into a broader health care package.

The Nelson Mullins federal advocacy team has extensive healthcare experience to bring clients an understanding of how the legislative, administrative, regulatory, and political processes operate on the Hill and at various state houses and, in turn, impact your industry and members. Please reach out to Jake Kohn for any questions regarding this topic.

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