Four associations representing hospitals plan the sue the U.S. Centers for Medicare and Medicaid Services to stop implementation of a new rule requiring health care providers to be more transparent about the costs of the services they provide.

President Donald Trump signed an executive order in June directing CMS and other federal agencies to develop rules requiring hospitals to publicly disclose costs for services negotiated with insurance companies. The idea is that patients could "shop around" for medical services if prices were more transparent, potentially saving money in the process.

CMS released the final rule based on the executive order on Monday. That same day, four hospital associations released a joint statement declaring their intention to sue the agency to stop the rule from going into effect.

"Today's rule mandating the public disclosure of privately negotiated rates between commercial health insurance companies and hospitals is a setback in efforts to provide patients with the most relevant information they need to make informed decisions about their care," the groups said. "Instead of helping patients know their out-of-pocket costs, this rule will introduce widespread confusion, accelerate anticompetitive behavior among health insurers, and stymie innovations in value-based care delivery."

The American Hospital Association, Association of American Medical Colleges, Children's Hospital Association and Federation of American Hospitals instead urged CMS "to work with hospitals, doctors, insurers, patients, and other stakeholders to identify solutions to provide patients with the information they need to make informed health care decisions and know what their expected out-of-pocket costs will be." The new rule, they said, "exceeds the Administration's authority."