Attorney General Mike Cox issued an Opinion on the validity in Michigan of same-sex marriages performed in other states and on the ability of such persons to adopt children (excerpt):
A marriage contracted between persons of the same sex in a state that recognizes same-sex marriages is not valid in the State of Michigan.
Couples of the same sex who marry in a state that recognizes same-sex marriages as valid are not legally authorized to adopt children in Michigan as a couple; one member of a same-sex couple may adopt a child in Michigan as a single person.