Income Limits

You cannot earn more than the adjusted gross income limits for your filing status to contribute to a Roth IRA. For 2010, if your adjusted gross income exceeds $120,000 and you are single, $177,000 and you are married filing jointly, or $10,000 and you are married filing separately, you cannot contribute.

Limitations on Investments

The IRS forbids the use of IRA funds to invest in collectibles or investments that will personally benefit you, such as investing in a house that you will live in.

Contribution Limits

The contribution limits are adjusted for changes in the cost of living each year. For 2010, the contribution limit is $5,000 if you are under age 50 and $6,000 if you are age 50 or older.

Considerations

The contribution limit applies to all IRA contributions--Roth and traditional--so each dollar you contribute to a traditional IRA reduces the amount you can contribute to a Roth IRA.

Misconceptions

The Roth IRA contribution limits are per person, even if your filing status is married filing jointly. For example, if you contribute $5,000 to your IRA, you have not limited your spouse's ability to put $5,000 in her IRA as well.

Source:

IRS: Roth IRA Rules

State Farm: Roth IRA