WASHINGTON (WUSA9) -- Same-sex couples can now get a tax credit for adopting a child. 

The credit comes out to a maximum of about $13,000 per child. It only applies when adopting a partner's child. 

This is a twist on an existing tax law.  Straight couples who are married can claim the adoption tax credit when they adopt a child together. However, they don't qualify when one spouse adopts the child of the other.