On instruction document:
H-1B Extensions:
USCISCalifornia Service Center
ATTN: H-1B Extensions
P.O. Box 10129
Laguna Niguel, CA 92607-1012
But confused at the same page (I am in Virginia):
Vermont Service Center Filings:
File Form I-129 with theVermont Service Center if thebeneficiary is or will be employed temporarily or receivingtraining in:Alabama, Arkansas, Connecticut, Delaware, the District ofColumbia, Florida, Georgia, Kentucky, Louisiana, Maine,Maryland, Massachusetts, Mississippi, New Hampshire, NewJersey, New Mexico, New York, North Carolina, Oklahoma,Pennsylvania, Puerto Rico, Rhode Island, South Carolina,Tennessee, Texas, Vermont, Virginia, U.S. Virgin Islands, orWest Virginia.
All other I-129 Cases:USCISVermont Service CenterATTN: I-12975 Lower Welden StreetSt. Albans, VT 05479-0001Premium
****Last yeat I submitted my 7th year extension to VSC and was approved there. ***********