I am an expat working in Malaysia all of 2015. I am paying Malaysian taxes and will be refunded all of my US Federal Taxes I have paid throughout the tax year. I have received my W2C. Box 1 is about $26,000 more on my W2C than it was on my W2. WHY?

Form w2c is used to make corrections to your w2 form when filing your return, you attach ONLY the W-2C if it corrected all of the information items.

If not, attach BOTH the original W-2 and the W-2C your ER , to correct the Form W-2 for you, has already submitted the Form W-2c with a separate Form W-3c;you neeeed to contact your ER/HR for more accurate info on the discrepancy.