Illinois Taxation of Same-Sex Married Couples

UPDATE 11/29/11: The Illinois Department of Revenue has finally issued guidance for same-sex civil unions. People in same-sex civil unions will be able to file as “married” on their Illinois tax returns. Click here for an article from the Chicago Tribune that talks more about this.

The article below was written on 11/21/11, prior to the release of this guidance.


Illinois now allows same-sex civil unions that have the same rights as any other married couple under state law.  Illinois also now recognizes same-sex marriages conducted outside the state.

How will this affect the tax returns of couples in same-sex civil unions or marriages in Illinois?  The answer is:  we don’t know yet.

In every other state that allows gay marriage or civil unions, same-sex couples must file as married on their state tax return.  But earlier this year, the Illinois Department of Revenue announced that partners in a civil union or gay marriage would NOT be allowed to file as married on their Illinois tax return.  This was what the Department said on its website earlier this year:

(Illinois Income Tax Act) Section 502(c) permits joint returns only when a joint return is filed federally.  The federal Defense of Marriage Act (which is being challenged in the courts) does not allow joint returns by partners to a civil union, so the IITA does not allow joint returns either.

This language has now been taken off the Department’s website.  Here is what the Department now says about same-sex civil unions:

The department is currently reviewing whether the Civil Union Act would allow joint filing of tax returns by same-sex couples under the Illinois Income Tax Act.

It would seem to me that same-sex couples would be allowed to file as married at the state level, considering that the act that authorized civil unions in Illinois was designed to treat same-sex civil unions in the same manner as opposite-sex married couples.  But we’ll have to see what the Department of Revenue’s final decision is on the matter.