For tax purposes, foster children can be viewed as the same as biological children. “You can claim a foster child dependent or adopted child dependent if the child was placed with you by one of these:
- An authorized placement agency
- Judgment, decree, or other court order"
Legal guardianship—where the child is placed with an adult by a court order— would meet this test (the child would be considered a “foster child” under this test), regardless of the actual biological relationship between the child and taxpayer. Reference: https://crsreports.congress.gov/product/pdf/IN/IN11853#:~:text=Legal%20guardianship%E2%80%94where%20....
