Superior Court Judge Carl J. Schuman denied Yale-New Haven Hosptial’s motion to dismiss the lawsuit brought against it by the Service Employees International Union, but dismissed nine of the 15 counts brought against the hospital by SEIU.

The suit is one of several challenging the hospital’s billing practices, the first of which was filed by Connecticut Attorney General Richard Blumenthal LAW ’73 18 months ago. The suit is part of a long-term conflict between the union — which represents 150 hospital dietary workers — and Yale-New Haven, persisting despite the conclusion of a 16-month contractual dispute last April.

Although many of the union’s counts were dismissed, SEIU attorney Daniel Livingston said the decision left the central claims of the case intact.

“The judge refused to dismiss the case,” Livingston said. “He left the core of the complaint, which is about the mistreatment by the hospital of indigent patients, under the free bed statute and the Connecticut Unfair Trade Practices Act.”

But Yale-New Haven spokesman Vincent Petrini said the dismissal of many of the union’s charges was a positive result for the hospital.

“Generally speaking, the court significantly limited the scope of the suit filed by the SEIU — and questioned the union’s standing in the suit,” Petrini said.

The hospital has changed its billing practices in response to the suits. It has revised its collection practices, closed many accounts and removed 92 percent of liens against former patients’ properties, Petrini said.

State law prohibits a hospital from collecting more than the cost of care from uninsured patients. While the union’s case asserted that the hospital was in violation of the law simply by billing for more than the cost of care, the judge dismissed some of the counts because poor patients did not actually pay above cost.

“The judge adopted a highly technical reading of the word ‘collected,’ saying you can’t bring a cause of action under that [law], unless you allege that he person has actually paid the money that hospital is trying to bill,” Livingston said.

But Livingston said some poor patients have paid more than the cost of care.

Livingston said the judge indicated that the union could still pursue its concerns over this specific count under the Connecticut Unfair Trade Practices Act, but dismissed the issue as a separate complaint.

The union’s next goal will be to pursue the case as a class action suit, he said.

“We’ll be seeking to have the suit class-certified, so we can speak on behalf of the thousands of people who have been mistreated,” Livington said.