taxmap/instr2/i8839-005.htm#TXMP57c6486e
Part II—Adoption Credit 
Line 2(p6)

The maximum adoption credit is $12,650 per child. If you and another person (other than your spouse if filing jointly) each paid qualified adoption expenses to adopt the same child, the $12,650 limit must be divided between the two of you. You can divide it in any way you both agree. Cross out the preprinted entry on line 2 and enter above line 2 your share of the $12,650 limit for that child.