WASHINGTON – The gap between the cost of renting a modest apartment and the wages of working families continues to widen, according to a new report from the National Low Income Housing Coalition.

“Out of Reach 2010” paints a gloomy picture for the nation’s nearly 38 million renters, who make up a third of U.S. households.

On average, a family must earn $38,355 a year, $18.44 an hour, to afford a simple two-bedroom apartment at the 2010 national average fair market rent of $959.

However, the average wage for U.S. renters is $14.44 an hour, down from $14.69 last year. Further, more than 60 percent of U.S. renters live in counties where even the average one-bedroom fair market rent of $805 isn’t affordable for average wage earners, the study found.

Minimum wage earners are at the greatest disadvantage. Under the standard measure of affordability — housing costs should account for no more than 30 percent of income — full-time minimum wage earners can’t afford one-bedroom apartments in any county in the country, even though Congress hiked the minimum wage from $6.55 an hour to $7.25 last year.

When adjusted for inflation, though, the average hourly wage fell by half a percentage point last year and probably will stagnate for the next few years, said economist Dean Baker, the co-director of the Center for Economic Policy and Research.

“So the ability of people to be able to afford decent housing is not likely to get any better” in the next few years, Baker said.

The findings help explain why the number of renters who moved in with family and friends, or “doubled up,” increased by 25 percent from 2005 to 2009.