As we said last week, pension assets can't be touched by creditors to pay off debts. But if a pension plan at a company in bankruptcy isn't fully funded, pension payments to formerly highly paid employees may be reduced.

Here's why: If a pension plan is terminated without sufficient money to pay all of the benefits, the Pension Benefit Guaranty Corp., a federal agency created to protect pension benefits, pays the pension plan's participants their benefits through an insurance fund. But it pays a benefit only up to a certain amount.

And that amount could be lower than the income that some retirees had been getting from their pensions before their plan's termination. In 2009, for example, the maximum guaranteed amount the PBGC will pay is $4,500 a month ($54,000 a year) -- and that's for retirees who start getting payments at age 65. The maximum would be lower for those collecting payments at a younger age or for those who include benefits for a survivor or a beneficiary.

To see the PBGC's "maximum monthly guarantee tables," go to pbgc.gov, click on "Workers & Retirees," and then click on "Maximum monthly guarantee tables" in the middle column.

Another problem: The PBGC generally doesn't guarantee early-retirement subsidies, which are frequently used by employers as an incentive to get older workers to leave the workplace before they reach the age at which they could max out their pension benefits. If your employer offers you an "enhanced pension" benefit, such as treating you as 60 years old instead of 55 upon retirement, you could lose that benefit if the plan is terminated and doesn't have enough assets to cover its payments to workers, Mr. Dichter says. In other words, you might start getting paid instead as if you retired at your actual age -- a lower amount.

So, "when people are evaluating buyout offers that include enhancements of their pensions, they have to take into account that those aren't guaranteed if there's a problem," Mr. Dichter says. That extra money you thought you could count on to fulfill a retirement dream, such as building a second home? Maybe you can't count on it after all.

If your employer wants to end a pension plan, the plan administrator has to tell you in writing.