NPR reported that the Department of Housing and Urban Development has conducted its annual survey of the nation's homeless population, including veterans. 

Every January, HUD picks a night for its "point-in time" survey of the homeless population. According to reporter Quail Lawrence, who covers veterans, thousands of volunteers traveled throughout New York City on a frigid night this week, counting the number of those living without permanent shelter. 

Lawrence said he went with the volunteers to Madison Square Park and Penn Station, and only met one veteran. The Department of Veterans Affairs uses the annual HUD report as a way to track veterans homelessness in the U.S. 

"[The VA] has said that maybe 12 percent of the homeless population are veterans … Predominantly Vietnam [War veterans] are among the homeless population," Lawrence reported. "There is a figure of about 48,000 thousand post-9/11 veterans who were helped out by the VA in some way, according to last year's statistics. They were either helped out for being homeless or on the verge of homelessness."

The most recent homelessness report from HUD was released in the fall of 2013. The department found that on any single night in January 2013, there were more than 57,000 veterans living without permanent housing.