A Cincinnati staffing agency that provides temp nurses to hospitals has sued Steward Health Care Systems, which operates Carney Hospital in Dorchester and St. Elizabeth’s Medical Center in Brighton, for the money it says the hospital system stopped paying for all of the healthcare professionals funneled to Steward hospitals following the outbreak of the Covid-19 pandemic.

In its suit, which was filed in Suffolk Superior Court, ProLink Healthcare charges that Steward slowed and then stopped its payments in 2022, ultimately to the tune of $45.6 million. ProLink alleges that Steward owes it $1.78 million specifically for healthcare professionals sent to St. Elizabeth’s and $50,093 for those sent to the Carney. However, its accounting of its total bill includes $2.5 million in arrears for North Shore Medical Center, now known as Salem Hospital, which is owned by Mass General Brigham, not Steward.

ProLink says it continued to honor its end of its deal with Steward and kept paying the nurses it had sent to Steward hospitals in Massachusetts and other states through Dec. 9, 2023, when the last of the healthcare professionals it had sent to a Steward hospital finished an assignment.

In its complaint, ProLink says the two sides signed a staffing agreement that went into effect in April 2020, as the first wave of Covid-19 was filling hospitals with patients. The company says it ramped up even more staffing after the omicron variant swept the country in November 2021, once again leading to an explosion of hospital use. In total, ProLink says, it sent 1,600 healthcare professionals on assignments at Steward hospitals in Massachusetts and elsewhere.

But, the company says, starting in early 2022, “Steward’s billing-persons became non-responsive and/or failed to address when payments would be made.”

By mid-November 2022, the company says, Steward was already up to $25.4 million in arrears. By May 20 of this year, ProLink alleges, Steward had hit $35.2 million in arrears - plus another $10 million in current balances. A date for Steward to respond to the suit has yet to be set by the court.