No, based on the information you provided. You did not say, but I am assuming that the baby lived with your girlfriend and did not live with you. While there are special rules for children born during the tax year (the child would have to live with you more than half the days it was alive during the year), if the baby was not living in your household, you would not satisfy the requirement that the child live with you for more than half the year.
You can claim a
child, relative, friend, fiancé, or other member of your household as a
dependent on your 2018 taxes as long as they meet either of the following sets
of requirements:
Qualifying child
- They are related to you;
- They aren't claimed as a
dependent by someone else;
- They are a U.S. citizen,
resident alien, U.S. national, or a Canadian or Mexican resident.
- They aren’t filing a joint
return with their spouse or are filing a joint return only to claim a
refund of withheld income tax or estimated tax paid;
- They are under the age of 19,
or 24 if a full-time student;
- No age limit for permanently
and totally disabled children.
- They live with you for more
than half the year (temporary absences from your home, while living at
school, still count as time living with you); and
- They didn't provide more than
half of their own support for the year.
Qualifying relative
- They don't have to be related
to you (despite the name).
- They aren't claimed as a
dependent by someone else.
- They are a U.S. citizen,
resident alien, national, or a Canadian or Mexican resident.
- They aren’t filing a joint
return with their spouse.
- They lived with you the
entire year.
- They made less than $4,150 in
2018.
- You provided more than half of
their financial support.
Note: Due to the Tax Cuts and Jobs Act of 2017,
you no longer receive a personal exemption for
your dependents. But there are other tax benefits, including the Child
Tax Credit and the new Credit for Other Dependents, you may be able to get when
you claim a dependent.
