The Ridenhour Prizes, established by the Nation Institute and the Fertel Foundation in honor of the veteran and journalist Ronald L. Ridenhour, who died in 1998, have been given to a range of government critics. In 2011, before the Snowden disclosures, Thomas Drake, a former N.S.A. official accused of leaking classified information, was given the truth-telling prize.

The awards are being presented April 30 at the National Press Club, and organizers say they are making efforts to have Mr. Snowden and Ms. Poitras, who is based in Berlin, appear remotely.

Mr. Snowden, who fled, ultimately, to Russia, faces prosecution if he returns to the United States. He has appeared via video link at a number of events in America; Ms. Poitras has not been back to the United States since the Snowden revelations. (Ms. Poitras, Mr. Greenwald and the journalist Jeremy Scahill, backed by the Internet billionaire Pierre Omidyar, founded The Intercept, which reports on national security issues.)

In describing the decision-making process, Danielle Brian, a member of the selection committee, said that the committee felt that Ms. Poitras had “been underappreciated — if not for Laura, we would not know Edward Snowden’s name.”

The decision to honor Mr. Snowden was more fraught, said Ms. Brian, who is executive director of the Project on Government Oversight.