This post pretty much supersedes all my other posts on gay marriage, now that the Supreme Court has declared same sex marriage legal in all states. This is a quick and dirty summation of how this affects taxes. This pretty much applies to State taxes, since Gay Marriage is already recognized for Federal taxes. Some States may interpret things differently than me, but I think most of what I discuss will stand up. As always, seek professional assistance and do not rely solely on this blog.
1. If you were married in a state that recognized gay marriage at the time you were married, the state you live in must now recognize this marriage and allow you to file Married Filing Jointly.
2. In addition, the option to file Single and Head of Household is generally off the table for legally married same sex couples except in limited circumstances.
3. Your marital status is determined as of 12/31 of the tax year, so if you are already legally married, it counts for 2015.
4. You must now divorce or legally separate in order to dissolve your marriage for tax purposes.
5. I would presume that you should be able to go back and amend tax returns for open years (generally 2012 and later) to file Married Filing Jointly and obtain refunds, assuming you were legally married on the last day of the tax year.
6. I don't believe you are obligated to go back and amend those returns as discussed above.
5 and 6 are particularly subject to interpretation by the individual States. If a lot of States interpret it differently, I'll consider a specific post covering each State.
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