Tax credit for adoption from foster care?

Hi. We have adopted twice internationally and once domestically, thru an agency, so we are quite familiar with the adoption tax credit. However, I'm not really sure how it works with an adoption thru foster care. It seems like I have read somewhere that if you adopt a child from the foster care system, you are entitled to the full amount of the tax credit even though you actually don't pay much, if anything, toward the adoption. Is this correct? Maybe I'm imagining things!