Form 8615 must be filed for anyone who meets all of
the following conditions.
1. You
had more than $2,100 of unearned income.
2. You
are required to file a tax return.
3. You
were either:
a) Under
age 18 at the end of 2018,
b) Age
18 at the end of 2018 and didn’t have earned income that was more than half of
your support, or
c) A
full-time student at least age 19 and under age 24 at the end of 2018 and
didn’t have earned income that was more than half of your support
4. At
least one of your parents was alive at the end of
20185. You
don't file a joint return for 2018.
https://www.irs.gov/instructions/i8615
