You don't add their income to your return. If he/she is required to file a return, he/she would file his/her own return & check someone else can claim tem on their tax return.
A dependent (under age 19, or under age 24 if a full-time student) has to file a Federal return if:
- Income (W2) is over $6,300
- Self-Employment income is over $400 (1099-misc)
- Unearned Income (Interest or dividend income) is over $1,050
States differ on filing requirements; you should check your State’s website for their filing requirements to determine if they need to file a State return.
Even if he/she does not need to file a return he/she may want to in order to get a refund for any taxes withheld from his/her 2016 wages.
Tax Filing Requirements for Children
https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Tax-Filing-Requirements-for-Children/I...