Is there a maximum percentage of income that can be contributed?

There is no upper limit on the percentage of income that can be contributed; however, IRAs have annual contribution limits. Roth IRA contributions may be further limited by your income if it is above certain limits. Your contributions are made post-tax, and your employer can’t deduct more than the amount of your available pay after the employer has made any other payroll deductions that have higher preference as required by law.