When do I have to start withdrawing from a traditional IRA?

While you can begin making qualified withdrawals from a traditional IRA at age 59½, you must start taking withdrawals that are known as "required minimum distributions" starting in the year you turn 70 ½. The amount of the distribution depends on how much you have saved in the account and your life expectancy, according to tables published by the IRS.

That's a major difference between a traditional IRA and a Roth IRA. If you own a Roth, you can leave the money in for as long as you want.