If a company has to amend a W2 for state taxes does this need to be reported to Federal also?

I have to have a W2-C issued that will change my state taxes from one state to another.

The W-2C is sent to BOTH the states in question and to the IRS.

When you get the W-2C, use only the W-2C when you prepare the tax returns.

Since the W2-C is for an older return 2003, do I have to refile with both states and federal?

No, just the state returns.