Can I claim my bf's 8 year old son? He's lived w/us over a year. My boyfriend is claiming his other 2 children. We got them through CPS, but neither parent has custody.

[Critter]

Sorry no ... if the BF is required to file a return only he can claim the child. 

[Hal_Al]

Critter#2 is correct. You cannot claim the child, unless the boyfriend's income is under $10,350. And even then it is highly unlikely you could claim the child. Even if the child did qualify as your dependent, he cannot be a qualifying child for the earned income credit, child tax credit or Head of Household filing status, because he is not related to you.