The F-I (student) visa falls in the category of non-immigrant visa and is issued for entry into the US “temporarily and solely for the purpose of study.” The status conferred to the holder of an F-1 visa, then, by its very nature, precludes employment.
Nevertheless, a student may find it necessary to work in order to fulfill the purpose of the visa. For example, there may be a drastic and unforeseen change which affects the ability to fund the studies; or, a course of study may require an internship or practical, on-site training in the form of paid employment in a business, organization, or industry. The Immigration & Naturalization Service (INS), recognizing this, has for many years allowed for employment by the F-1 student where necessary and justified.