You want to spend enough of that money to make a meaningful contribution to your lifestyle in retirement. And you want to keep from spending too much, which could cause your IRA or investment portfolio to run out of money. It’s important to consider that increased life expectancies lead to longer retirements. At age 70, for example, with a 65-year-old spouse, the chances are that one of you will live for another 23 years. Therefore, you need a plan that will allow your money to last as long as you do.