When the U.S. Census Bureau updated its model for calculating the nation’s poverty rate, it arrived at an unexpected result: nearly twice as many older Americans qualify as poor than had been previously thought. The new data suggest that 16 percent of those 65 and older are poor. Under the old formula, which failed to accurately reflect housing and medical costs, the poverty rate for older Americans stood at 9 percent.

The Los Angeles Times reports :

[M]edical costs are pushing low-income seniors living on fixed incomes over the brink, said Kathleen S. Short, a U.S. Census Bureau economist.

For many, that fixed income amounts to Social Security benefits and not much else, due to the declining numbers of Americans who have a traditional pension.

Nationwide, across all demographic groups, the new formula yielded greater numbers of Americans living in poverty: from 46.6 million, determined in 2010 under the old formula, to 49.1 million per the report released this week—an increase of 2.5 million.

Experts were surprised by the bureau’s finding that, under the new formula, poverty in the western states outpaced that of states in the South, where lower housing costs accounted for the difference. One bright spot: the Census Bureau now estimates that the percentage of children living in poverty is lower than had been previously thought—but not by a lot. The 2010 report placed the number of children living below the federal poverty line at 23 percent. Under the new formula, that share falls to 18 percent.