The Bill That Keeps Growing
Medicare Advantage was designed to give seniors more choices and insurers more flexibility, but federal auditors have spent years documenting a less flattering reality: private health plans have systematically billed the government for sicker patients than their records can support. The Centers for Medicare and Medicaid Services has renewed pressure on insurers to repay billions in what auditors classify as improper payments, reigniting a fight that touches some of the largest health insurance companies operating in the United States.
The Office of Inspector General, which oversees Medicare program integrity, has repeatedly flagged risk adjustment as the mechanism driving most of the excess billing. Insurers receive higher monthly payments from the federal government for enrollees with more serious diagnoses. The financial incentive to document – or in some cases overstate – patient illness is substantial, and audits have found that diagnoses added to justify higher payments often lack supporting clinical records.
The scale of disputed payments runs into the tens of billions of dollars.
How Risk Adjustment Became a Liability
Risk adjustment itself is not a scam. The system was built to prevent insurers from cherry-picking healthy enrollees and abandoning sicker patients. If every plan received the same flat payment per member, companies would have every reason to avoid costly patients. So CMS pays more for enrollees with conditions like diabetes, heart failure, and chronic kidney disease. The problem arises when diagnosis codes appear in billing data without any corresponding treatment, referral, or clinical note to back them up.
Auditors have found that some insurers relied heavily on in-home health assessments conducted by third-party vendors. These assessments, often brief and disconnected from a patient’s regular care, generated diagnosis codes that boosted risk scores without the enrollee ever receiving treatment for the flagged condition. The OIG has described this practice as a structural flaw in how the program validates the data it pays against. When a diagnosis never results in a prescription, a specialist visit, or even a follow-up note, it raises an obvious question about whether the condition was ever genuinely identified.
CMS finalized a methodology called RADV – Risk Adjustment Data Validation – to claw back overpayments identified through contract-level audits. The rule has faced years of legal and lobbying resistance from insurers who argued the extrapolation method used to calculate repayments was unfair. A federal court challenge delayed implementation, and the rule that eventually went into effect was narrower than what auditors originally proposed. Even so, CMS projects the audits will recover meaningful sums over the coming years, with enforcement gradually expanding to cover more contract years and more plans.
Industry Pushback and the Political Dimension
Insurers have not accepted the auditor findings quietly. The industry’s argument centers on two points: that the government’s audit methodology overstates error rates by failing to account for conditions that are genuinely present but documented differently across care settings, and that abrupt repayment demands could destabilize plans serving millions of beneficiaries. These are not frivolous objections – health record documentation varies enormously across provider networks, and auditing a single chart does not always capture a patient’s full medical picture.
The political dimension complicates enforcement. Medicare Advantage now covers more than half of all Medicare beneficiaries, a milestone that makes any serious disruption to the program a third-rail issue for members of Congress in both parties. Insurers have used that enrollment growth as an implicit argument against aggressive clawbacks, suggesting that repayment demands could translate into reduced benefits or higher premiums for seniors. Whether that connection is as direct as the industry implies is debatable, but the political framing has worked well enough to slow the pace of enforcement for years.
What has changed recently is the appetite at the federal level to treat overbilling as a structural problem rather than a case-by-case compliance matter. The Biden administration pushed RADV further than previous administrations. The Trump administration’s current posture on Medicare Advantage enforcement is still taking shape, but budget pressures across federal health programs – including ongoing scrutiny of Medicaid spending – have kept the question of improper payments squarely on the agenda. When the government is cutting costs elsewhere, it becomes harder to leave a well-documented source of overpayments untouched.
What Comes Next for Insurers and Enrollees
The audits are accelerating, the repayment calculations are getting more precise, and the insurers with the largest Medicare Advantage footprints – companies managing millions of contracts – face the greatest exposure. Plans that built their revenue models around aggressive risk score optimization are now recalibrating, and some have already disclosed audit-related financial liabilities in their regulatory filings. The open question is whether enforcement will move fast enough to actually change behavior, or whether the gap between what auditors find and what the government collects will remain wide enough that overbilling stays financially rational for the companies doing it.
