NVC My category changed from f2a to f2b but i got welcome letter from NVC.

The determinative factor in whether you can go through with the interview is whether you will be considered under the age of 21. Age is frozen when the priority date is reached. You are also given credit for the length of time that the I-130 petition pended with U.S.C.I.S. before approval. If in doing the calculations you are under the age of 21 when your age is frozen, you can immigrate under the F-2A category.Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.