NPR receives grants from the Corporation for Public Broadcasting.
According to CPB, in 2009 11.3% of the aggregate revenues of all public radio broadcasting stations were funded from federal sources, principally through CPB; in 2012 10.9% of the revenues for Public Radio came from federal sources.
Funding isn’t held hostage for the purpose of controlling content or anything like that, but NPR receives funds from the CPB, and the CPB receives funds from the government. I’m not sure why believing otherwise is so important to you.