Question: Can my wife and I share one Roth IRA and contribute as much as $10,000 a year to it, or must we each have separate IRAs with the normal $5,000-a-year contribution cap? We’d prefer one account to pool our resources and diversify more, because several mutual funds have minimums we can’t individually get into, but could by pooling resources. Thanks for your help! Jake, Madison, WI 

Answer: No, each of you needs to have your own Roth IRA. As the IRS puts it on its website, “You cannot both participate in the same IRA.” The same holds for other kinds of retirement savings plans, such as a 401(k) and 403(b). You can still keep fees down by doing business with financial firms that offer rock-bottom fees on accounts and products.