See IRS Publication 501 Dependents, Standard Deduction, and Filing Information page 13 - https://www.irs.gov/pub/irs-pdf/p501.pdf#page=13
Children of divorced or separated parents (or parents who live apart).
If statements (1) through (4) are all true, only the noncustodial parent can:
• Claim the child as a dependent, and
• Claim the child as a qualifying child for the child tax credit or the credit for other dependents.
However, this doesn’t allow the noncustodial parent to claim head of household filing status, the credit for child and dependent care expenses, the exclusion for dependent care benefits, the earned income credit, or the health coverage tax credit
