Most of NPR's revenue comes from the private sector; 22 percent from sponsorships and 34 percent from station programming fees. Only about 7 percent of its revenue is generated through grants and contributions.
NPR stations, however, rely more heavily on federal and state grants. CPB funding constitutes 10 percent of their funding; federal, state and local government funding constitutes about 6 percent of a station's revenue source while 32 percent comes from individuals and 21 percent from businesses.
NPR executives argue that federal funding is key to their operations, but Republicans have seized on comments made by Schiller, who says in the hidden camera video that NPR and most of its member stations would survive without such funding.
Schiller, then-president of the NPR Foundation and senior vice president for development, was caught on tape calling the Tea Party "xenophobic" and "seriously racist people" who are "fanatically involved in people's personal lives."
He goes on to say that the Republican Party has been hijacked by the Tea Party and laments the demise of intellectualism, particularly in the GOP.
NPR's president and chief executive Vivian Schiller (no relation to Ron Schiller) resigned in the wake of the scandal.
House GOP leaders have for years attempted to cut funding for what many of them see as a liberal-leaning broadcast operation.
House Republicans made a proposal in November to strip federal funding for NPR after the radio station fired controversial commentator Juan Williams for comments he made about Muslims. That bill didn't pass.
ABC News' John Parkinson contributed to this report.