How and when can we take the dependent child tax deduction?

Again, as outlined above, what is best is to consult with a tax advisor and preferably a CPA.  Generally, you would utilize the deduction in the year you took placement of the child, but that is not always the case and your case-specific facts will matter greatly.  You may apply to the IRs for an adoption taxpayer identification number if you do not yet have a social security number for your child.