2012 Limits for IRA Contributions and Deductions

Traditional IRA and Roth IRA Contribution Limits for 2012

IRA limits and maximum IRA contribution

Under 50 before the end of 2012
The most you can contribute to either the Traditional IRA or the Roth IRA is whichever is smallest, $5,000 or your taxable compensation for the year.

You can put the funds into both a Traditional and a Roth IRA as long is both together don't add up to more than the limit.

When you do this, you are effectively changing your gross income.

This means that the maximum contribution to a Roth IRA and the maximum deductible contribution to a traditional IRA may be reduced.

Over 50 years old before the end of 2012

Everything is the same as above except the limit is whichever is the smaller $6,000  the other amount is still or your taxable compensation for 2012.

For 2012
Read about the effect of modified Adjusted Gross Income on deductible contributions if you are covered with a retirement plan at work here.

Read about the effect of modified adjusted gross income on deductible contributions if you are not covered by a retirement plan at work here.

Read about the effect of modified adjusted gross income of Roth RA contributions here.

There are a lot of specifics in the 107 page printable file entitled IRS Publication 590.