The Child Status Protection Act (CSPA) amends the Immigration and Nationality Act by permitting an applicant for certain benefits to retain classification as a “child” under the Act, even if he or she has reached the age of 21. Prior to CSPA, once a child turned 21 years of age, that child "aged-out" and was no longer able to immigrate (or adjust status) along with his family. CSPA eliminates this problem by "freezing the age" of immediate relative children when their petitioning U.S. citizen parent submits a visa petition on their behalf. CSPA uses a mathematical formula which allows the amount of time that a visa petition was pending to be subtracted from a child's age.
Public Law 107-208, 116 Stat. 927