Investigative Reporting on Medicare Advantage Billing Practices

In the fall of 2022, Wall Street Journal reporters sought access to Medicare data from the Centers for Medicare and Medicaid Services (CMS) to investigate potential overbilling in the Medicare Advantage program. Christopher Weaver, an investigative journalist, explained that the team requested CMS treat them as researchers, allowing access to detailed Medicare and Medicaid claims over a 12-year span. This database included comprehensive details on prescriptions, doctor visits, and hospitalizations.

The investigation highlighted significant financial implications for the Medicare program, which had a federal cost of $1.12 trillion in 2024. Approximately $500 billion to $600 billion of this budget was directed towards Medicare Advantage, managed by private insurers. Enrollment figures that year showed 69.7 million people, with over half opting for Medicare Advantage or similar plans.

With data access granted in August 2023, the investigative team, including health insurance reporter Anna Wilde Mathews and senior editor Mark Maremont, uncovered questionable billing tactics by major insurers such as UnitedHealth Group and CVS Health. These practices incurred billions in taxpayer costs and potentially exposed patients to risks. The data also revealed that insurers profited by claiming payments for conditions that patients did not have, prominently involving major providers like UnitedHealth, which led Medicare Advantage enrollment.

Impact and Recognition

The investigative work was commended with a nomination for the 2025 Pulitzer Prize in investigative reporting and received recognition for exposing how insurers manipulated the Medicare Advantage billing system for financial gain. The reporting drew attention to a discrepancy identified by KFF, estimating that payments to Medicare Advantage plans exceeded traditional Medicare costs by roughly 20%, leading to additional spending of $84 billion.

The Senate Judiciary Committee cited the journal's reporting in a 2025 report on Medicare Advantage overbilling, acknowledging the collaborative efforts of Wall Street Journal and STAT News journalists. This report noted strategies used by insurers to increase profit margins.

Weaver emphasized the necessity of having direct access to CMS data for investigations of this scale and advised journalists interested in similar work to start with smaller projects. The complex nature of analyzing extensive programming lines, along with interviews and document verification, underscored the challenges and significant resources required for such in-depth reporting.