Bottom line: you may make a full $5500 contribution to your ROTH IRA.
Roth IRA Modified Adjusted Gross Income (MAGI)
When the IRS speaks of various income levels it is referring to modified adjusted gross income. To figure your modified adjusted gross income, you will need your adjusted gross income (AGI) from your tax return. You then add back several adjustments, including the deduction for half your self employment tax.
For more on ROTH MAGI, see:
https://www.irs.com/articles/what-modified-adjusted-gross-income
Dependents are allowed to make a ROTH IRA contribution.
