Can I get a child tax credit for my financee' children.

[zielot111]

My fiancee is a stay at home mom, with two  children under 17 from a prior relationship.  they live with us 100% of the year and I cover 100% of their expenses.  can i get the child tax credit for them and claim them?

[xmasbaby0]

No.    You cannot get the CTC for your GF's children.   If your GF and the children lived with you the entire year in 2022, and she earned less than $4400, (not counting Social Security) then you may be able to claim them and get the $500 credit for other dependents for each of them---but that is all.  You cannot use them to file as Head of Household, get earned income credit or the child tax credit.  Sorry.  If you become legally married that will be different.

https://ttlc.intuit.com/questions/4499708-what-is-the-500-credit-for-other-dependents-family-tax-cre...

[DoninGA]

Since the children are not your biological children and you are not married to the mother of the children you are not eligible for the Child Tax Credit on your tax return.

You can claim the children as your dependents and the mother of the children as a dependent under the Qualifying Relative rules where you may be eligible for the Other Dependent credit of $500 for each dependent.  Provided that they meet all the rules for a Qualifying Relative.

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 $4,400 (social security does not count) in 2022
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.

[Hal_Al]

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.

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

As others have said, legal step children are the same as biological children.  After you marry, her children will meet the relationship test and you can claim them as Qualifying Children, whether you file a joint or separate tax return.