Nearly 40 percent of Americans 65 and over have a mortgage while housing accounts for half of the typical senior home owner’s wealth, a study unveiled by the Mortgage Bankers Association reveals.

For the “young old” (ages 65 to 69) still shelling out for their homes, mortgage payments take up 18 percent of their incomes on average. That burden swells by nearly double to 34 percent for the old old (ages 90 and over).

Likely showing how aging consumes assets, the average wealth of home owners in their late 60s amounts to $631,000 but dips to $464,000 for seniors above 90.

Seniors appeared to have been immune from a direct hit during the meltdown.

“With little mortgage debt and constant inflation-adjusted income from Social Security, the home ownership of older Americans has emerged from the recession relatively unscathed. However, their children’s generation has taken a direct hit,” the report said.

The study was based on interviews with 25,000 Americans in 2010 and the numbers reflect that year.