Households overall face a substantial “retirement deficit” that will grow even deeper if Social Security benefit levels are reduced from their current amounts, according to the Employee Benefit Research Institute.

It said that retirement savings shortfalls are especially severe due to factors including higher costs of living an especially long time—what it called longevity risk—and the potential cost of home health care or nursing home costs.

For those on the verge of retirement, average shortfalls vary from a joint $39,000 for a married couple to $34,000 for single males and $63,000 for single females.

However, risk level varies according to various projected life paths, some of which result in a conclusion of no shortfall. Looking at only those patterns at risk of a shortage, the shortfalls nearly double, it said.