If your daughter was a high school in 2018 and/or started college in mid-August, then my answer is correct. If she wasn't, please see TomD8's answer below.
Yes, she is your dependent as long as:
- She didn't claim herself on her income tax return or she wasn't claimed as a dependent by someone else.
- She's a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
- She isn't filing a joint return with their spouse.
- She's under the age of 19 (or 24 for full-time students). She's considered a full-time student if her 1098-T Tuition Box 8 is checked.
- She didn't provide more than half of her own support for the year (i.e. housing, food, clothing, medical insurance, utilities, etc.).
See also Can I claim education expenses for my dependent?
Related information:
[Edited 1-31-19|9:05 am PST]
