By Tara Bannow | October 5, 2026
In a courtroom drama that could reshape the financial landscape of the Medicare Advantage (MA) program, the federal government faced intense scrutiny this week. A three-judge panel of the U.S. Court of Appeals for the Fifth Circuit signaled profound skepticism toward the Department of Health and Human Services (HHS) regarding the agency’s controversial audit rule—a policy designed to reclaim billions in overpayments to private insurers.
The hearing marks the latest chapter in Humana v. Kennedy, a landmark case that pits the nation’s second-largest Medicare Advantage provider against the federal government. At the heart of the dispute is the "Risk Adjustment Data Validation" (RADV) rule, a regulatory mechanism intended to ensure that the payments made to private insurers for treating Medicare beneficiaries accurately reflect the health status of those patients.
As the legal proceedings unfold, the stakes for the healthcare industry are astronomical. With private insurers increasingly reliant on government contracts, the ability of HHS to claw back funds through audits has become a central tension in the public-private partnership that defines modern Medicare.
The Core Dispute: Procedural Fairness vs. Fiscal Oversight
The legal battle centers on a procedural claim that has broader implications for how federal agencies promulgate regulations. Humana, supported by a coalition of industry interests, argues that the final RADV rule—finalized under the Trump administration’s overarching efforts to tighten oversight—diverged so significantly from the original proposed rule that it violated the Administrative Procedure Act (APA).
According to Humana, the government failed to provide stakeholders with adequate "notice and comment" opportunities. The insurer contends that the final iteration of the rule introduced methodology shifts that were not adequately previewed, effectively blindsiding the industry and imposing financial burdens that were never part of the original regulatory discourse.
During Monday’s oral arguments, the Fifth Circuit judges appeared to lean toward this interpretation. The panel expressed concern that the gap between what was proposed and what was ultimately enacted deprived insurers of their right to engage in a transparent, democratic rulemaking process. If the court ultimately rules in favor of Humana, it would affirm a lower court’s decision from September 2025, which invalidated the rule entirely.
A Chronology of the RADV Conflict
To understand the severity of this legal impasse, one must look at the timeline of events that brought the healthcare sector to this tipping point:
- Pre-2023: For years, the Centers for Medicare & Medicaid Services (CMS) faced pressure from the Office of Inspector General (OIG) to address the high rate of "improper payments" in Medicare Advantage. OIG reports consistently highlighted how insurers could inflate risk scores to receive higher payments.
- The Proposed Rule: HHS moved to strengthen the RADV process, signaling an intent to conduct more rigorous audits and retroactively recover funds identified as overpayments.
- The 2023 Lawsuit: Following the finalization of the RADV rule, Humana filed Humana v. Kennedy, alleging that the regulation was not only procedurally flawed but also economically punitive.
- September 2025 (The District Court Ruling): A federal district judge handed a major victory to Humana, vacating the RADV rule. The court cited the agency’s failure to adhere to standard notice-and-comment protocols.
- November 2025: The government, determined to uphold its oversight authority, filed an appeal to the Fifth Circuit.
- October 2026 (The Current Hearing): The Fifth Circuit panel hears arguments, with judges questioning the government’s justifications for the rule’s final methodology.
Supporting Data: The Multi-Billion Dollar Question
The fiscal implications of this case are massive. Medicare Advantage has become the primary growth engine for many of the nation’s largest insurers. Because payments to these plans are adjusted based on the "risk" or health complexity of the patient—a process known as risk adjustment—the accuracy of those scores is the single most important variable in the program’s budget.
According to government audits, the "error rate" in these payments has often been estimated in the billions. HHS has argued that without the RADV rule, the Medicare Trust Fund remains vulnerable to systemic overpayments, where insurers are rewarded for coding patients as "sicker" than they actually are to boost reimbursement rates.
However, insurers argue that the audits are inherently biased. They point to the "Fee-for-Service (FFS) Adjuster"—a mechanism that would account for coding differences between traditional Medicare and Medicare Advantage. The industry argues that if the government does not account for these differences, the audits are fundamentally unfair. The government’s decision to omit this adjuster in the final rule was a primary driver for the current litigation.
Official Responses and Industry Sentiment
The government’s position, presented during the hearing, is that the rule is a necessary instrument of fiscal responsibility. Departmental lawyers emphasized that CMS has a legal mandate to protect the Medicare Trust Fund and that the final rule was a reasonable evolution based on public feedback and the agency’s technical expertise.
Conversely, Humana and its industry allies maintain that the rule is an example of regulatory overreach. In statements released throughout the litigation, the industry has argued that while they support accountability, they cannot operate under rules that are retroactively applied or created without a clear, transparent administrative path.
"The integrity of the rulemaking process is not just about the specific outcome, but about the stability of the healthcare market," said one industry analyst familiar with the case. "When the rules of the game change overnight, it prevents insurers from pricing their products correctly, which eventually impacts the seniors who rely on these plans."
Implications: The Future of Medicare Advantage
If the Fifth Circuit confirms the lower court’s decision to vacate the rule, the impact will be felt far beyond Humana.
1. A Chilling Effect on Oversight
A loss for the government would likely discourage future attempts to tighten audit procedures. It would signal to federal agencies that any significant deviation from a proposed rule could result in total invalidation, forcing regulators to be significantly more cautious—or perhaps more timid—in their oversight of private contractors.
2. Financial Consequences for the Trust Fund
If the RADV rule remains vacated, the federal government loses its primary tool for clawing back billions in identified overpayments. This could force Congress to intervene, either by passing new legislation to clarify audit authority or by requiring CMS to restart the entire rulemaking process—a multi-year endeavor that would leave the program in a state of regulatory limbo.
3. Investor Confidence
Medicare Advantage insurers have seen their stock prices fluctuate wildly throughout this litigation. For Wall Street, the legal status of the RADV rule is a proxy for the future profitability of the entire Medicare Advantage sector. Investors are closely watching the Fifth Circuit, knowing that a permanent invalidation of the rule could mean significant windfall profits for insurers, while a reversal would necessitate a massive shift in how these companies model their future earnings.
4. The Patient Impact
Ultimately, the conflict over risk adjustment affects the benefits seniors receive. If insurers are forced to pay back billions in overpayments, they may respond by reducing the supplemental benefits—such as dental, vision, or hearing coverage—that have made Medicare Advantage so popular. Alternatively, if the government’s oversight is stifled, the program’s long-term sustainability may be called into question, potentially triggering higher premiums or reduced federal subsidies.
As the Fifth Circuit deliberates, the healthcare industry waits with bated breath. The ruling, expected in the coming months, will define the power balance between the federal government and the private entities that now provide coverage to over half of all Medicare beneficiaries. For now, the "Humana v. Kennedy" case stands as a stark reminder of the complexities inherent in managing a healthcare system that is neither fully public nor fully private, but caught in the constant friction of both.
