Medicare Advantage Risk Adjustment Payment Authority Failure Through Unsupported Diagnosis Codes Submitted Without Corresponding Clinical Documentation at Aetna

Medicare Advantage is the private plan alternative to traditional Medicare. The Centers for Medicare and Medicaid Services pays Medicare Advantage plan sponsors a risk-adjusted capitated rate for each enrolled beneficiary — a fixed amount per member per month that varies based on the beneficiary's documented health status. The risk adjustment system uses diagnosis codes submitted by plan sponsors to determine each beneficiary's risk score. A beneficiary with documented chronic conditions receives a higher risk score than a healthy beneficiary. The plan sponsor receives a higher payment. The system is designed to ensure that plans covering sicker populations are adequately compensated and that plans are not financially rewarded for enrolling only healthy beneficiaries.

The diagnosis code is the instrument through which health status is represented to CMS. A code submitted for a beneficiary asserts that a clinician documented that condition during a qualifying encounter within the relevant data collection period. CMS accepts the submitted codes as the evidentiary basis for the risk score and the associated payment. The code authorizes the payment. The clinical documentation is the condition that makes that authorization legitimate. The code does not carry the documentation. It represents that the documentation exists.

DOJ announced in 2025 that Aetna agreed to pay $117.7 million to resolve False Claims Act allegations that it submitted or retained unsupported diagnosis codes in its Medicare Advantage risk adjustment data. The allegations encompassed two distinct failure modes: submitting codes for conditions that lacked corresponding clinical documentation establishing that the condition was present and documented during a qualifying encounter, and failing to delete codes that Aetna identified as unsupported — codes that the company's own review processes flagged as lacking adequate documentation but that remained in the risk adjustment submissions. In both cases, the diagnosis code authorized a payment the underlying clinical record did not support.

The diagnosis code functions as a payment credential in the Medicare Advantage risk adjustment system. CMS accepts submitted codes as establishing the health status that determines the risk-adjusted payment rate. The code encodes the representation that a clinician documented the specified condition during a qualifying encounter. It does not encode the clinical documentation itself. The relying party — CMS — has no mechanism at the point of payment authorization to verify that the documentation the code represents is present in the patient record. The payment follows the code.

The failure condition is the absence of a correspondence requirement at the point of reliance. The diagnosis code is accepted as sufficient to authorize the risk-adjusted payment. Whether the clinical encounter occurred, whether the condition was documented, whether the documentation meets the standards required to support the code — none of these conditions are verified by CMS at the point of payment. They are represented by the submitting plan sponsor. The plan sponsor's financial interest in the outcome of that representation is direct: a higher-acuity code produces a higher payment. The evidentiary boundary between the code and the clinical record it is required to represent is not enforced at the point of payment authorization.

Aetna's own review processes identified codes that lacked adequate supporting documentation. The failure to delete those codes is a distinct condition: the plan sponsor possessed internal knowledge that the correspondence between the code and the clinical record was absent, and submitted or retained the codes regardless. The credential was not merely unsupported — it was known to be unsupported at the point of submission.

Aetna agreed to pay $117.7 million to resolve the False Claims Act allegations without admitting liability. The settlement is the second-largest individual Medicare Advantage upcoding settlement in the catalog, following Kaiser Permanente's $556 million resolution. DOJ's Civil Division has pursued Medicare Advantage risk adjustment fraud as a sustained enforcement priority; MedPAC estimated in 2025 that systemic Medicare Advantage upcoding results in approximately $84 billion in excess federal payments annually. The Aetna settlement addresses one named plan sponsor's conduct within a structural failure condition that operates across the Medicare Advantage program.

• Aetna settled False Claims Act allegations for $117.7 million in 2025, resolving claims that it submitted unsupported diagnosis codes and failed to delete codes known to lack clinical documentation — in both cases, the diagnosis code authorized a risk-adjusted payment the underlying clinical record did not support
• The diagnosis code is a payment credential in the Medicare Advantage risk adjustment system: it represents that a clinician documented a specific condition during a qualifying encounter, and CMS pays the associated risk-adjusted rate on the basis of that representation without independent verification of the underlying clinical record at the point of payment
• The failure condition is structural: the correspondence between the diagnosis code and the clinical documentation it represents is not enforced at the point of payment authorization — the code is accepted as sufficient; the record is not verified
• Aetna's own review processes identified unsupported codes; the failure to delete those codes represents a condition where the plan sponsor possessed direct knowledge that the credential lacked correspondence to the underlying record and submitted or retained it regardless
• The $117.7 million settlement is the second-largest individual Medicare Advantage upcoding resolution in the catalog; MedPAC estimated $84 billion in systemic excess MA payments annually as of 2025 — the named-entity settlement addresses individual conduct within a program-wide structural failure
• The diagnosis code as payment credential is structurally distinct from provider enrollment credentials and cybersecurity compliance credentials documented elsewhere in the catalog: the credential is generated at the point of clinical documentation, submitted by the plan sponsor, and accepted by CMS as the sole evidentiary basis for a financial transfer — the correspondence gap is built into the payment architecture