Can both my sister and myself claim my dad as a dependent?

In the case where there are siblings as shared caregivers of one elderly parent, , only one sibling can take the exemption for the parent. An agreement needs to be reached yearly as to which sibling will take the exemption on their return. The sibling taking the exemption will need to file Form 2120, Multiple Support Declaration, and have all of the other siblings sign the form claiming that they will not take the exemption on their own return.