You must meet the IRA contribution rules to contribute to an IRA. If you want to contribute to a traditional IRA, you must meet the IRA contribution rules for traditional IRA.
IRA_Contribution_Rules.html
Below are the Roth IRA contribution rules. What are the differences between Roth IRA contribution rules vs traditional IRA contribution rules?
Roth_IRA_Contribution_Rules.html
If you are covered by a pension plan at work such as a 401k, your traditional IRA contributions may or may not be deductible depending on the filing status and AGI. The IRS rules for IRA and retirement plan at work such as a 401k is found in the IRS Publication 17 page 118.
IRS_Rules_for_IRA_and_401k.html