My girlfriend receives Social Security for three daughters whose father’s deceased she has lived with me for the last year. Am I able to claim her kids as a dependent

[jero_1983]

If I claim them, I am just worried about it possibly screwing up the Social Security for the kids

[Hal_Al · Accepted solution]

Q.  Am I able to claim her kids as  dependents?

A. Probably not.

There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit and student status test, a relationship test and a residence test. Only a QC qualifies a taxpayer for the Earned Income Credit and the Child Tax Credit. The Other dependent (qualifying relative) credit is worth (up to) $500 per dependent and is non-refundable.  That is, it can only be used to reduce an actual tax liability.

You can't claim the children as QC, because they are not related.  A person can still be a Qualifying relative dependent, if not a Qualifying Child, if he meets the 6 tests for claiming a dependent:

1. Closely Related OR live with the taxpayer ALL year
2. The child's gross taxable income for the year must be less than $4700 (2023) ($5050 for 2024). Social security does not (usually) count as income. 
3. The taxpayer must have provided more than 1/2 his support

In either case:

4. He must be a US citizen or resident of the US, Canada or Mexico
5. He must not file a joint return with his spouse or be claiming a dependent of his own
6. He must not be the qualifying child of another taxpayer

He must have a US social security number or tax identification number (TIN)

In addition to the above requirements, to claim your girlfriend's children, they must meet all of the above requirements and:
--- she must not be required to file a return,
--- she does not file a return claiming the children

Nontaxable Social security doesn't count as income, for the income test, but social security money  spent on support   does count as support not provided by you, for the support test.  

The IRS has a worksheet that can be used to help with the support calculation. See: http://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf The support value of a home is the fair market rental value, divided by the number of occupants.

Whether claiming them will  screw up the Social Security for the kids, is beyond the scope of this forum (and my knowledge) but I doubt that it will. 

[Opus 17]

Social security payments for surviving minors are based on the deceased parent's work history and are not needs-based.  If you did qualify to claim the children as dependents, it would not affect their survivor benefits.

SSI (supplemental security income) is needs based, and could be affected by the recipient of the benefit being supported by another person.  That's probably not the case here, but it would not hurt to double check.