At the time of I-526 applications, you do not need to be married. You can always add your wife before you apply for conditional permanent residency. If you do not add her to your application at that time, you can always sponsor your wife once you obtain your green card. USCIS on their website clearly states: To bring your spouse (husband or wife) to live in the United States as a green card holder (permanent resident), you must be either a United States citizen or green cardholder.