The study by the Employee Benefit Research Institute (EBRI) in collaboration with the Milbank Memorial Fund said the aggregate deficit in retiree income during the decade ending 2030 would be at least $400 billion.

The study suggested a possible fix – at least for middle-income Americans: set aside 5% of annual compensation in addition to any other retirement benefits to which they may be entitled. However, the savings approach won’t work for many in the lower income brackets. In fact, most at risk are low-income single women, who typically just don’t have enough disposable income to fund a proper savings program. In most cases, they would have to save 25% or more of their pay annually to adequately fund basic living expenses in retirement (including nursing home or home health care costs), according to the study.

As a general rule, couples and those with higher income fared best. Also, the odds of having sufficient income to afford basic expenditures throughout retirement with an additional savings of 5% of compensation are significantly higher for those in the youngest cohorts. This confidence level ranges from a low of approximately 30% for those in the lowest income quartiles that are on the verge of retirement to more than 85% for those with above median income in the 1961-1965 birth segment.

Achieving a 90% confidence level for sufficient retirement income would require added savings of no more than 10% for median couples above the lowest income quartile born since 1945. Added savings of no more than 5% would assure a 75% certainty for these groups.

Finally, despite growing interest in ways for retirees to turn their housing equity into income, neither annuitizing the value of their home, nor selling it when required to provide added income, eliminates the projected shortfall in retirement income adequacy for all individuals, EBRI reported.

For more information, go to http://www.ebri.org .