My husband is retired, and I work part-time. Can we contribute to a Roth IRA for him this year? — Martha Chamberlain, Lanesville, Ind.

Even if just one spouse has a paycheck, you can both put $5,000 ($6,000 if you're 50 or older) in Roth IRAs every year as long as your modified adjusted gross income (for joint filers) is below $169,000. However, you can't invest more than what you earn from your part-time job. Opening a Roth is a smart move, even for retirees, says tax attorney Kaye Thomas of Fairmark.com. Unlike with a traditional IRA, you never have to make withdrawals. And if you don't need the money, your heirs will enjoy tax-free growth too, though kids who inherit a Roth will have to withdraw the money eventually.

— Tali Yahalom