You are asking a question that should be answered by the programs that are providing the SNAP benefits and other benefits to your parents. We cannot know the rules of the programs they are receiving benefits from. We can tell you that claiming your parents would only get you a non-refundable $500 credit for each of them that would lower your tax liability.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**