Q. I filed for my mother to come to the United States and on April 2009 she was granted a green card. My question is, when will she be able to file for citizenship?

January 20, 2012 | Naturalization

A. Your mother is eligible for naturalization after being a lawful permanent resident for five years. The date she became a permanent resident is on her green card. She can file her Application for Naturalization, USCIS form N-400, 90 days before completing the five years.
Your mother can naturalize after just three years if she has been married to, and living with the same U.S. citizen husband for three years. Under the three-year rule, before filing her application, she must have been married for three years. If that’s the case, she can apply to naturalize 90 days before the third anniversary of her becoming a permanent resident.