Hello, I am 25 years old and I was about to apply for citizenship when I was told by a friend that I should already be a citizen since my mom was naturalized when I was 16 years old. My father had already passed away by then. I wanted to know what do I do? Should I just go and apply for a passport? I been in the US for 23 years. I went through the school system here.. I want to go on vacation but I don't know what to do. I was about to renew my indian passport which has been expired since I was 14. Please help me

This is what's called Derivative Citizenship (as you may have "derived" citizenship through your parent(s)). The laws of derivative citizenship have changed many times throughout the years in the US. It sounds like you may fall under the newest law called the Child Citizenship Act (CCA). To fall under the laws of this act you have to be under 18 as of Feb. 21, 2001. If you meet this age requirement these are the rules for you:

-at least one parent is a US citizen either by birth or naturalization
-if you were illegitimate at birth you must have been legitimated by your father by the time you reached 16
-you were under 18 as of Feb 21, 2001
-you were unmarried (at least unmarried at the time that you met all these other conditions)
-you were a lawful permanent resident (you had your Green Card)
-you were residing in the legal and physical custody of your citizen parent
-if you were adopted, you had to be in the legal and physical custody of your citizen parent before the age of 16 and living with your adopted parents for at least 2 years

Here is a link with the Rules: http://www.corporateprobono.org/archive/resources/resource1343.pdf

Review the rules that apply to you based on you year of birth.

Also, here is a link to the gov't page for the CCA: http://www.uscis.gov/portal/site/uscis/menuitem.5af9bb95919f35e66f614176543f6d1a/?vgnextoid=1fb596981298d010VgnVCM10000048f3d6a1RCR D