The two major types of IRAs are traditional IRAs and Roth IRAs. Both allow you to contribute as much as $5,500 in 2016 (unchanged from 2015). You must have at least as much taxable compensation as the amount of your IRA contribution. But if you are married filing jointly, your spouse can also contribute to an IRA, even if he or she has little or no taxable compensation, as long as your combined compensation is at least equal to your total contributions. The law also allows taxpayers age 50 and older to make additional "catch-up" contributions. These folks can contribute up to $6,500 in 2016 (unchanged from 2015).