You likely filed with the wrong status as 'single' and should have amend the return to the correct the filing status. Follow the rules for filing when married to a non-resident alien spouse. Once your spouse has an ITIN or SSN, you would file using the filing status of Married filing Separately, Head of Household (if qualifying), or Married Filing Jointly if you make the election to treat the spouse as resident alien. You generally have 3 years from the date the return was filed to submit an amended return.