What does it cost and how long does it take to get a visitor's visa extension to US from Canada?

The cost for a visitor visa extension in the U.S. is typically $370, which is the filing fee for Form I-539. The processing time can vary, generally taking anywhere from 2 to 6 months, depending on the U.S. Citizenship and Immigration Services (USCIS) workload and other factors. It's important to apply well before your current visa expires to avoid any unlawful presence in the U.S.