What is the maximum I can contribute?

Each account has different limitations:

Roth and Traditional IRAs:

If you are younger than 50 years old, Roth and Traditional IRAs have a maximum allowed contribution of $5,500 per year (in year 2017).

If you are older than 50 years old, Roth and Traditional IRAs typically allow a catch-up contribution to provide for a maximum allowed contribution of $6,500 per year (in year 2017).

If you have multiple Roth and Traditional IRAs the total annual contribution to all accounts must never exceed the maximum annual contribution limit set by the IRS for the calendar year.  If you over contribute to either account penalties may apply until the account is corrected.

Depending on your filing status or MAGI (modified adjusted gross income) you may qualify for different amounts of contribution allowed per account type (Roth or Traditional IRAs). For example, you may not be allowed to make any Roth IRA contributions, but as an alternative you may be allowed to make Traditional IRA contributions to make up your total contribution limit.

IRS Website - IRA Contribution Limits