My uncle(my father's brother) applied for our green card. We are 4 brothers. My birth year is 1981, my bothers birth years are 1985, 1987 and 1990. The petition was approved in Aug 2001. Last month my uncle received an invoice from NVC for the payment of immigrant visa processing fee. The invoice has my parents names along with my three brother's names except mine. I was expecting only my youngest brother name to be in there. So I called the NVC and they said that my other two brothers are protected under CSPA.I am a bit confused on how the CSPA is calculated. Also I asked the NVC if there is any date before which they need to be in the US, he said that there is nothing like that and unless they hear from us within a year we are fine since they have already qualified.Can you confirm these?