Does my domestic partner need to receive more than half of his financial support from me for the entire year or only from the moment when I claim him as a tax dependent?

[NCperson]

the year 

[DoninGA · Accepted solution]

To claim a non-relative as a dependent they must meet all the requirements under the Qualifying Relative rules.

To be a Qualifying Relative -

1. The person cannot be your qualifying child or the qualifying child of any other taxpayer. A child is not the qualifying child of any other taxpayer if the child's parent (or any other person for whom the child is defined as a qualifying child) is not required to file an income tax return or files an income tax return only to get a refund on income tax withheld.
2. The person either (a) must be related to you or (b) must live with you all year as a member of your household.
3. The person's gross income for the year must be less than $4,150 (social security does not count) in 2018
4. You must provide more than half of the person's total support for the year.
5. The person must be a U.S. citizen or a U.S., Canada, or Mexico resident for some part of the year.
6. The person must not file a joint return with their spouse.

[rjs]

quhae27 wrote:
". . . or only from the moment when I claim him as a tax dependent?"

You can't claim someone as a dependent for part of the year. You either claim him for the entire year or you don't claim him at all. There is no "moment" during the year when you start to claim a dependent.