The Corporation for Public Broadcasting said Friday it would shut down next year, effectively ending its half-century role as a backer of NPR, PBS and local radio and TV stations across the United States.

The organization will continue to support public broadcasters through a transition period that will end in January, said Patricia Harrison, its president and chief executive, in a statement.

“Public media has been one of the most trusted institutions in American life, providing educational opportunity, emergency alerts, civil discourse, and cultural connection to every corner of the country,” Ms. Harrison said. “We are deeply grateful to our partners across the system for their resilience, leadership, and unwavering dedication to serving the American people.”

The Corporation for Public Broadcasting has been in the cross hairs of Republicans for decades. Conservative policy advocates, legislators and presidents argued persistently that the public shouldn’t be responsible for financing media they perceived as having a liberal bias. But repeated attempts to defund public broadcasters failed, until this year.

Congress voted last month to claw back more than $500 million of the organization’s annual funding in a narrow vote that played out along party lines. That forced the corporation into a cash crunch.

The Corporation for Public Broadcasting is among the first casualties of the claw back, which puts public radio and TV stations across the United States at risk of going dark. Scores of stations rely on government financing to fund their operations, especially those in rural areas. That has prompted public media advocates to raise concerns that listeners and viewers in those areas will be without access to news, cultural programming and potentially lifesaving emergency alerts.