The U.S. Supreme Court on Monday declined to hear a challenge to the Independent Payment Advisory Board (IPAM) --– the Obamacare body critics have dubbed a "death panel" -- leaving intact a ruling by the 9th U.S. Circuit Court of Appeals that threw out the lawsuit, Reuters reported.

The San Francisco-based appellate court said in August that Arizona plaintiffs Nick Coons and Eric Novack were unable to show that they had suffered damages over which they could sue; backed by the conservative Goldwater Institute, the business owner and orthopedic surgeon had also objected to the individual mandate, which requires Americans to obtain health insurance.

In December, 25 Republican lawmakers supported Coons and Novack's effort with an amicus brief in the court, the Hill recalled. They, too, questioned the role of IPAM, which is designed to cut Medicare costs.

"As a physician with more than 30 years of experience, I find the ability of this board to intervene in the relationship doctors have with their patients alarming," Rep. Phil Roe said at a press conference at the time. "I have serious concerns that this unelected, unaccountable bureaucracy could have a devastating impact on seniors' access to care, and I hope the court will hear this case," the lawmaker from Tennessee added.

Monday's unsigned order is a victory for the administration, but President Barack Obama's signature healthcare legislation still faces another obstacle as the nation's highest tribunal weighs a separate case challenging health-insurance subsidies that are key to its implementation, Reuters judged.

The Goldwater Institute, meanwhile, said it would again sue over IPAM once the board begins to take action, something it may not do for several years. The panel is not designed to make decisions until Medicare spending increases to certain amounts, Politico revealed.

Christina Sandefur, a senior attorney at the Goldwater Institute, told the Washington publication that the Arizona-based organization would continue to follow its developments.

"This case is not dead; we're simply in a holding pattern," she noted. "We will bring this challenge again once the Independent Payment Advisory Board takes action."