San Francisco, CA immigration attorney Mary Jane Weaver talks about visa stamps and why someone needs one even after the immigration service has approved a petition on her behalf. She explains that the process of transitioning from a work visa approval to obtaining an actual visa can be confusing for individuals, employers, and foreign nationals. Essentially, while you can obtain an approval for a specific type of visa, if you intend to travel or enter the United States and have not been here before, you need to engage with a different agency. The initial petition is usually filed with the USCIS in the United States. However, to obtain a visa in your passport and gain entry or re-entry into the United States, you must apply for a visa at the American Embassy, typically located in your home country or abroad.