The government requires diagnoses be supported and validated by the medical record. The lawsuit alleges that United increased the amount of money it received by reviewing medical records from providers and employing diagnosis coders to review them and add diagnosis codes that the providers did not report. The lawsuit also contends that UnitedHealth also entered agreements with some fee-for-service providers, providing them with incentive payments based on revenues that the company received from Medicare, thus incentivizing these providers to increase the number of diagnoses they recorded. The lawsuit estimates that through these practices, UnitedHealth received at least $1 billion in payments that it was not entitled to. "As the nation's largest Medicare Advantage Organization, UHG received substantial overpayments based upon untruthful and inaccurate information about the health status of those enrolled in its plans," said Acting US Attorney James P. Kennedy Jr for the Western District of New York.