If lower, your taxable compensation for the year. You can contribute to a traditional IRA regardless of how much money you make. However, you don't qualify to open or contribute to a Roth IRA account if you make too much money. If you make too much money, you may still be able to contribute to a Roth IRA through a strategy called a clandestine Roth IRA.
Yes, a person under 18 can contribute to a Roth IRA or a traditional IRA as long as they meet earned income requirements and do not exceed income limits. This table shows if your contribution to a Roth IRA is affected by the amount of your modified AGI as calculated for the Roth IRA. A spousal IRA is an IRA open to a spouse with no income of their own, usually by providing unpaid work to their household.