New York's comptroller says $513 million in improper Medicaid payments and missed revenue over four years and another $361 million in questionable transactions were identified by auditors.
Comptroller Thomas DiNapoli says Medicaid, insuring nearly 6.4 million low-income New Yorkers, was found with waste throughout the system.
It's projected to cost $62 billion this year, with $22.4 billion paid by the state.
The report says audits from 2011 through February 2015 show "recurring deficiencies" in the computer system processing claims and missed drug rebates and discounts.
State Medicaid director Jason Helgerson says most criticisms are old, most have been addressed, and health officials are committed to recouping all lost money.
He notes the comptroller's contract review slowed the change to a new computer system.