If your plans in the U.S. have changed, you will need to go through the necessary procedures to change your status and get an approved application by the USCIS. If you have been lawfully admitted to the U.S. with a nonimmigrant visa, your status remains valid, you have not violated conditions of your status and have not committed crimes that would make you ineligible, you may submit an application for a change in status before your Form I-94 (Arrival-Departure Record) expires. Your passport must be valid during your requested period of stay in the new status. You are not eligible to change your status if you were admitted in C, D, K1, K2, S, TWOV, WT, WB, J1, M1 or Q2 Visa since you must depart on or before Form I-94 expires. Processing times vary so check on the official USCIS website for when you should apply.
The potential U.S. employer must file I-129 petition on behalf of the foreign worker before Form I-94 expires. Petition I-129 shows that the foreign worker meets the requirements for changing U.S. status and will perform the work for the U.S. employer.
Applicant must file Form I-539 for all other categories. Application for one I-539 may include family members requesting the same change in status. Family members include spouse and unmarried children under 21 years old.
For more information on requirements and specific visa instructions, please refer to USCIS website