Question:
My son and I have U.S. Green Card based on my marriage to U.S. citizen husband. We are now conditional permanent residents. It is true that the conditional Green Card will expires after two years for my son also, unless necessary steps are taken?
Answer:
Aliens who obtain permanent residence (Green Card) based upon a petition filed by a U.S. citizen spouse may be subject to conditional residence status for two years. Permanent residence will be conditional, if the duration of the marriage has been less than two years at the time permanent residence is granted. This means that it will expire after two years, unless the Form I-751 is filed and approved. This allows the USCIS to double check and reassess whether the marriage was real at the time of its inception.
This same conditional grant of permanent residence is extended to children who obtain permanent residence based upon the marriage of that parent to a U.S. citizen, when the marriage is less than two years in duration. If the parent's marriage is not real, then the children of the alien can not obtain any immigration benefits as the result of the marriage.
http://www.greencardfamily.com/question/question2014/Conditional-Permanent-Resident-Status_0217.htm