If you obtained your green card based on marriage to a US citizen and thereafter wish to become a US citizen, you will become eligible to do so at anytime within the 90 days of the third anniversary of the day you became a legal resident on Jan 2013. In your case, you can file for citizenship anytime after October 2015.This assumes that you are still married to your wife at that time.
Answered on Apr 02nd, 2013 at 2:07 PM