Only a U.S. Citizen who is at least 21 years old is eligible to petition for his/her parents to become lawful permanent residents. Lawful permanent residents are not eligible to petition for his/her parents to become lawful permanent residents.
Overview of Immigration Process
There is a three-step process for a parent to become a legal immigrant, unless he/she is already in the U.S. in lawful status (see Combined Processing below):
The USCIS must approve an immigrant visa petition (Form I-130, Petition for Alien Relative) that you file for your parent.
An immigrant visa must be available based on the date the immigrant visa application was filed. (Note: Parents are considered immediate relatives and visas in this category are immediately available.)
If the parent is outside the U.S. when the visa petition is approved and when an immigrant visa number (if required) becomes available, the spouse will be notified by the Department of State’s National Visa Center to complete the processing for an immigrant visa. If the spouse is legally inside the U.S. when the visa petition is approved and when an immigrant visa number (if required) becomes available, he or she may apply for adjustment of status to that of a lawful permanent resident with the appropriate USCIS Regional Service Center.
Combined Processing for Parents Already in the U.S.
Since a parent is considered an immediate relative and is immediately eligible for an immigrant visa, the USCIS allows for Combined Processing this category. This means that if the parent is legally in the U.S. (through a lawful admission or parole) at the time of filing the Form I-130, Petition for Alien Relative, he/she may also file for adjustment of status at the same time. Combined Processing is only available to beneficiaries/applicants who are in the U.S.