You only file one federal return that must have all your states attached.  You will need to file an amended return for 2015 that adds California and computes your correct state taxes.  How much you owe to CA and how much to OH depends on where you lived, when you moved, and whether you were a resident or non-resident.  But you have to have both state modules installed at the same time and prepare all three returns together so that it calculates correctly.

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