"What do you know about reapplying to Social Security?" my 67-year-old friend asked me.

I honestly admitted I'd never run into the question before and would have to give some thought to the question.

I learned that a fellow named Scott Burns, a journalist who writes on personal financial questions in newspapers and online, has recently published his opinions on the subject of reapplication, especially for those in their late 60s and early 70s, who started receiving their Social Security benefits at age 62.

His thesis is this: You cannot find a better annuity anywhere than the annuity you'd receive for life from Social Security given its annual adjustments for inflation. On this point Burns is correct, though there are some commercial products that come close and may be more flexible and more appropriate for some, depending on their objectives. Also, the taxation on the distribution from an immediate commercial annuity is typically lower in most cases than the taxation on Social Security benefits.

Burns calculates that if a 68-year-old individual who had taken Social Security since age 62 were to repay all of his Social Security payments for the last six years to Social Security and reapply for benefits, he would receive the equivalent of a lifetime annuity paying 9.5 percent per year with adjustments for inflation. That kind of annuity payout is not available commercially from any private insurance company.

In the one case I studied the current Social Security recipient would have to repay to Social Security $125,000 to $150,000 to get the 9.5 percent lifetime benefit.

Returning $125,000 or more to Social Security raises questions about the best use of your money and about your assumptions, especially life expectancy. You have to live at least another 10 years to get your money back. If you died within 10 years, you would have forfeited all the capital and denied heirs any access to the "unused" funds.

Returning money to Social Security in this case assumes that the inflation adjustment will continue and that current taxation on Social Security benefits will remain unchanged. What if Congress in an effort to resolve some of the federal government's deficit problems decides to means test Social Security benefits and adopt more aggressive rates of taxation for those with other sources of income or higher benefits?