(Reuters) Amid all the gloom and doom about forced retirement, skyrocketing healthcare costs and nest egg-cracking financial markets, there’s another threat facing baby boomers: future tax liabilities.

The generation that has depended solely on 401(k)s and tax-deferred individual retirement accounts may not realize how much of a tax hit it will take when it starts withdrawing the money and living on it.

With the prospect of rising tax rates after the Bush tax cuts expire, some retirees could find themselves paying even more in taxes than they did when they were working. “It continues to surprise our clients that taxes are that big of an expense in retirement,” says Mark Davis of SunTrust Investment Services, Inc.

Note: Read our discussion guidelines before commenting.