In general, you may apply to change your nonimmigrant status if you were lawfully admitted into the United States with a nonimmigrant visa, your nonimmigrant status remains valid, and you have not committed any crimes that would make you ineligible.

(VWPP) - Visa Waiver Pilot Program (or the Guam Visa Waiver Program)
D - As a crewman
C - As an alien in transit or in transit without a visa
K - As a fiancé of a U.S. citizen or dependent of a fiancé
S - As an informant (and accompanying family) on terrorism or organized crime

If you are an international exchange visitor (J visa) you may not change your nonimmigrant status if you were admitted to the United States to receive graduate medical training, unless you receive a special waiver. In addition, some exchange visitors must meet a foreign residence requirement before they are allowed to change status. This means that some international exchange visitors must leave the United States and go back to their home country for a minimum of two years before applying to come to the United States as a temporary worker or an immigrant. If you are an exchange visitor and are required to meet the foreign residence requirement, you must receive a waiver if you wish to change your nonimmigrant status without returning home. If you do not receive a waiver, then you may only apply to change to the A (Diplomatic and other government officials, and their families and employees) or G (Representatives to international organizations and their families and employees) nonimmigrant categories. For more information on international exchange visitors, please see Waiver of the Foreign Residence Requirement for Exchange Visitors.

If you are a vocational student (M visa), you may not apply to become an academic student (F visa category). You also may not apply to change from the vocational student visa category to a temporary worker visa category (H) if it was the training you received as a vocational student in the United States that made you qualified for the temporary worker position.

You do not need to apply to change your nonimmigrant status if you were admitted into the United States for business reasons (B-1 visa), and you wish to remain in the United States for pleasure before your authorized stay expires.

If you are in the United States as the spouse or child of someone in the following nonimmigrant visa categories, you do not need to apply to change your status if you wish to attend school in the United States (as long as your parent or spouse maintains their original nonimmigrant status).