If you have $17,400 of earned income, that is taxable unless you're Married Filing Jointly.
In addition, Social security (including SSDI) becomes taxable when your income, including 1/2 your social security, reaches:
Married Filing Jointly(MFJ): $32,000
Single or head of household: $25,000
Married Filing Separately and lived with your spouse at any time during the tax year: $0
