Yes, your wife will need an ITIN, according to the IRS General ITIN Information:
If you do not have a SSN and are not eligible to obtain a SSN, but you have a requirement to furnish a federal tax identification number or file a federal income tax return, you must apply for an ITIN.
You file the ITIN application with the tax return attached:
Because you are filing your tax return as an attachment to your ITIN application, you should not mail your return to the address listed in the Form 1040, 1040A or 1040EZ instructions. Instead, send your return, Form W-7 and proof of identity and foreign status documents to: Internal Revenue Service, Austin Service Center, ITIN Operation....
You may also apply using the services of an IRS-authorized Acceptance Agent or visit some key IRS Taxpayer Assistance Center in lieu of mailing your information to the IRS in Austin.
See the full document for details, or call the IRS toll-free at 1-800-829-1040.
For instructions regarding filing status, see IRS Publication 17 :
You are considered married for the whole year if, on the last day of your tax year, you and your spouse meet any one of the following tests.
- You are married and living together.
- You are living together in a common law marriage recognized in the state where you now live or in the state where the common law marriage began.
- You are married and living apart, but not legally separated under a decree of divorce or separate maintenance.
- You are separated under an interlocutory (not final) decree of divorce.
Generally speaking, you use your marital status at the end of the year for the whole year.