The website that I have listed below is a great source for researching state tax issues for the LGBT community. Since many states do not follow federal tax law, it is often the case where a couple has to file MFJ on their federal return but can’t file joint on their state return because the state that they live in does not recognize gay marriage.
This is the case in the state of Michigan. LGBT couples who are legally married and are MI residents cannot file a joint MI tax return. They will file a joint federal and two MI returns as single individuals.
For further information, check out this website or drop me a line.