Liz Weston

Dear Liz: I’m 54 and plan on retiring at 55 with a government pension. I have about $450,000 in a 457(b) deferred compensation plan. I owe about $220,000 on my home. I would like to pay off my 15-year, 2.5% interest mortgage. This would free up $1,900 a month and leave us debt-free. Everyone I’ve spoken to says this is a bad idea since I’d lose my mortgage interest deduction and I’d be “investing” in a low-interest vehicle (my mortgage). My only other obligation is my daughter’s college education, and I’m paying that in cash. Am I crazy to pay off this mortgage?

Answer: You’re not crazy, but you probably haven’t thought this all the way through.

The money in your deferred compensation plan hasn’t been taxed. Withdrawing enough to pay off your mortgage in one lump sum would shove you into a higher tax bracket and require you to take out considerably more than $220,000 to pay the tax bill. You could easily end up paying a marginal federal tax rate of 33% plus any applicable state tax — all to pay off a 2.5% loan.

There are a few scenarios where using tax-deferred money to pay off a mortgage can make sense. Some people have so much saved in retirement plans that the required minimum distributions at age 70½ would push them into high tax brackets and cause more of their Social Security to be taxed. They also may have paid down their mortgage to the point where they’re no longer getting a tax break.

In those instances, it may be worth withdrawing some money earlier than required to ease the later tax bill. The math involved can be complex, though, and the decisions are irreversible, so anyone contemplating such a move should have it reviewed by a fee-only financial advisor who is familiar with these calculations.

In fact, it’s a good idea to get an objective second opinion from a fiduciary any time you’re considering tapping a retirement fund. (Fiduciaries are advisors who pledge to put your interests ahead of your own.)

During your meeting, you also should review the other aspects of your retirement plan. How will you pay for health insurance in the decade before you qualify for Medicare? If you’re a federal employee, you should be eligible for retiree health insurance but your premiums may rise once you quit work. If you’re planning to buy individual coverage through a healthcare exchange, what will you do if that’s yanked away or becomes unaffordable? How will you pay for long-term care if you need it, since that’s not covered by health insurance or Medicare?

You can get referrals to fee-only financial planners from the National Assn. of Personal Financial Advisors at napfa.org. You can find fee-only planners who charge by the hour at Garrett Planning Network, garrettplanningnetwork.com.