It's not unusual for the age gap between husband and wife to be 10 years, 20 years, or more. Financial planners say the age difference calls for an unconventional retirement plan. Here is what they advise:

* Insurance. A couple approaching retirement might normally reduce their life insurance coverage because their children are now adults. But if a family will depend on the younger partner's earnings, that could be a reason to increase coverage instead.

Both partners should consider buying long-term care insurance.

* Pension planning. These couples have to make decisions about how to manage their pension money earlier than couples who are the same age. With a younger spouse, the couple might have higher costs for a longer period of time. They must anticipate cash-flow requirements and decide how to fund the expenses. Planners writing in Business Week say the younger partner should keep at least 60 percent of savings in stocks.

The older partner should leave 401(k) money in the company plan. After age 55 it can be withdrawn at will without penalties. With a rollover IRA, a retiree younger than 59 1/2 has to follow a strict withdrawal plan or pay a penalty.

New IRS rules work to their advantage. They can choose a payout schedule that sets up a withdrawal plan based on the younger partner's life expectancy. That allows the money to last longer.