There are limits on the amount of income one can make during a given year—and the limits change from year to year. Please visit the IRS website for details.
Note: The IRS maintains a page that provides additional information about Roth IRAs. You can find that page here
http://www.irs.gov/Retirement-Plans/Roth-IRAs and you will want to link on a regular basis. The IRS might update its site and change the location of the information.
Another option is for your credit union to update the answer to this question yearly.
