Do we need to amend both of our Ohio returns from MFS to MFJ or just amend one?

[user40914591]

Recently learned that we need to amend our federal return from MFS to MFJ and that we only to amend one of the federal returns.  Therefore, we have to amend our Ohio returns from MFS to MFJ, so do we needed to amend both or just one?  Does having to amend our return change the answer to the number of federal returns that need to be amended to MFJ.  In addition, do we need to amend last years Ohio return before be file this years Ohio return?

[Critter]

You will only amend one federal and one state return to switch from MFS to MFJ  ... by amended one it automatically amends the other. 

And you can mail in the 2016 amended returns before the 2015 amended returns... however they must all be filed separately and will take 16 weeks or more to process.