Democrats are blaming Republican Monroe County Executive Cheryl Dinolfo for a billing problem at Monroe Community Hospital.
The county is hiring an accounting firm to recoup at least some of the $3.9 million that went uncollected for more than six months.
County officials say the backlog in collections from Medicaid and insurers happened during the transition to a new electronic record system.
Dinolfo's Democratic opponent for re-election, Adam Bello, wants the New York State Medicaid Inspector General to investigate.