It depends on what you mean by "not immediate kin".
To qualify for the Child Tax Credit, your child must fit all of these requirements:
- Be under age 17 at the end of the tax year
- Is your son, daughter, stepchild, foster child, adopted child, brother, sister, stepbrother, stepsister, half-brother, half-sister, or a descendant of any of them (for example, a grandchild, niece, or nephew)
- Has his or her own Social Security Number
- Children with ITINs don't qualify, but may instead be eligible for the $500 Credit for Other Dependents
- Lived with you for more than half the year
- Didn't support him/herself (i.e., didn't pay more than half their own expenses)
- Is a U.S. citizen, U.S. national, or U.S. resident alien
- Residents of Canada or Mexico wouldn't qualify
Up to $1,400 of the credit is refundable and is phased-in based on your earned income. In most cases, you must have $2,500 or more of earned income to be eligible for any portion of the refundable Child Tax Credit.
The $2,000 per-child credit is reduced once your AGI reaches $200,000 (or $400,000 if you're filing jointly with your spouse).