Fairview Health Services is seeking damages in excess of $75,000 from UnitedHealth Group’s Change Healthcare Technologies LLC, alleging that Fairview had significant operational and financial harm following a cyberattack last year.

Hackers attacked Eden Prairie-based UnitedHealth Group through its Change Healthcare division, the Pioneer Press reported at the time. The medical payment processing company is used to submit and process billions of insurance claims a year, according to the Associated Press.

The attack disrupted payment and claims processing around the country, interfering with providers’ ability to file claims and get paid. UnitedHealth disconnected the affected systems to limit damage and paid a $22 million ransom in bitcoin, said UnitedHealth CEO Andrew Witty last year.

Fairview officials said the incident caused the Minneapolis-based company substantial harm.

“While our teams worked tirelessly to protect patients from further impact and to maintain continuity of care, this event created confusion for patients and raised serious concerns about the potential compromise of patient data, which we view as a critical breach of trust,” Fairview Health Services said in a statement.The lawsuit, filed in Ramsey County District Court on Tuesday, alleges that Change Healthcare failed to meet its obligations under agreements made with Fairview because of its inability to perform services following the attack.

“Fairview now brings this action to make itself whole and to curtail the irreparable harm that CHT’s breaches have and will cause to Fairview, its patients, and its providers,” the lawsuit reads.

UnitedHealth Group officials, in a statement Thursday, called the lawsuit “baseless and we intend to defend ourselves vigorously.”

Fairview also uses Change Healthcare to help provide anesthesia service, including with billing and collecting payments for such services. The lawsuit alleges the cyberattack resulted in Change Healthcare being unable to access and process anesthesia service for more than six months.

“As a result of CHT’s failure to perform the services it had promised, the interruption in billing for anesthesia services resulted in Fairview having remaining balances from the gap in coverage of over seven million dollars,” the lawsuit claims. “Because of CHT’s inaction, Fairview has been unable to collect balances that it would have been able to had CHT performed its obligations under the parties’ contracts and the industry standards CHT was obligated to meet.”

The lawsuit also alleges that Fairview will never be paid for some of the health care it provided because of the failure of Change Healthcare’s services.

Fairview uses Change Healthcare services as a “clearinghouse to help submit complaint claims for clinical services to the third-party payers responsible for paying Fairview.” Change Healthcare also updates claims to ensure they are complete and compliant for Fairview’s billing services, according to the complaint.

Fairview isn’t the only group suing over the cyberattack. The online site the HIPAA Journal reported that dozens of lawsuits have been filed against UnitedHealth Group and Change Healthcare in connection with the data breach.