If your wife has stayed in the US for more than five years, she is a resident. You can e-file your return by filing jointly.
If your wife does not stay in the US for more than 5 years by 2018, she would be treated as a nonresident. If you want to file jointly with her, you would need to attach a statement to your tax return. See Nonresident to resident. This way, you cannot e-file. You have to submit this statement along with all the print-out tax forms to the IRS by mail. To print out, see https://ttlc.intuit.com/replies/3338601