US Employment Rules for F1 Students
Most international students in the United States hold an F-1 visa, which is the U.S. non-immigrant student visa. F-1 students are allowed to work in the United States, but only under certain conditions and in accordance with complex guidelines and restrictions issued by the United States Citizenship and Immigration Service (USCIS).

Generally, all employment is contingent on remaining within the terms and restrictions of your F-1 visa. There are several categories of employment during the term of your stay as an F-1 student in the United States. On-campus employment is the most freely available, and then there are four categories of off-campus employment: optional practical training (OPT), curricular practical training (CPT), severe economic hardship, and approved international organizations.

On-Campus Employment
1) Part-time
Students may work on-campus (only) for 20 hours a week, during the first nine months. After that, they may be permitted to work off-campus strictly on a case-by-case basis, with the approval of the Designated School Official (DSO) of the university, who represents the US Citizenship and Immigration Services (USCIS)

On-campus employment is the category most freely permitted by the USCIS regulations, and it does not require USCIS approval. However, although F-1 status includes an on-campus employment privilege, on-campus employment opportunities at most schools are limited. Even if you can obtain a job on campus, you may not rely on it to prove financial resources for the year, and often these jobs are not related to your studies. Many schools do require that you obtain permission from the International Student Office prior to accepting any on-campus employment

Optional Practical Training (OPT)
International students in the U.S. in valid F-1 immigration status are permitted to work off-campus in optional practical training (OPT) status both during and after completion of their degree. Rules established by the U.S. Citizenship and Immigration Service (USCIS) govern the implementation of OPT, and all OPT employment requires prior authorization from USCIS and the school’s International Student Office.

Student can apply for OPT after being enrolled for at least 9 months, but cannot begin employment until the receipt of Employment Authorization Document (EAD) from USCIS and enrollment for at least a year. Student need not have a job offer to apply for your OPT EAD, and OPT employment can occur anywhere in the US. Its always advisable to start early—USCIS takes up to 90 days to process the application—and it’s important to work closely with school’s International Student Office. As with everything for a student in U.S., permission is based on maintaining lawful F-1 status, and that’s where International Student Office helps to maintain that status throughout the stay.

General OPT Requirements

•Employment must be “directly related” to the student’s major

•Student must maintain lawful F-1 status

•Student must apply for OPT before completion of all work towards a degree

•Students who have engaged in 12 months or more of full-time Curricular Practical Training (CPT) are not eligible for OPT

•OPT is permitted for up to 12 months full-time in total – part-time OPT (while still in school) reduces available full-time OPT by half of the amount of part-time work (for instance, if you work part time for 6 months, you can work full-time for up to 9 months)

IMP NOTE: Students have to be mindful of the travel regulations governing F-1 students on OPT. If they leave the country after completion of degree, but before receiving the EAD and obtaining a job, they may not be readmitted. Students can leave the country after completion of degree if they have EAD and a job, but have to make sure that they bring everything that will be needed to get back in (including valid passport, valid EAD card, valid F1 visa, all the I-20s with page 3 endorsed for travel by international student advisor within the past 6 months, and a letter of employment, including dates of employment and salary).

Curricular Practical Training (CPT)
Curricular Practical Training (CPT) is an off-campus employment option for F-1 students when the practical training is an integral part of the established curriculum or academic program. CPT employment is defined as “alternative work/study, internship, cooperative education, or any other type of required internship or practicum that is offered by sponsoring employers through cooperative agreements with the school.” To qualify, the work experience must be required for your degree, or academic credit must awarded. And yes, you can get paid for CPT employment. Prior authorization by your school’s international student office and notification to the U.S. Citizenship and Immigration Service (USCIS) is required.
To be eligible for CPT employment:

•Student must have been enrolled in school full-time for one year on valid F-1 status (except for graduate students where the program requires immediate CPT)

•The CPT employment must be an integral part of the degree program or requirement for a course for which they receive academic credit

•Students must have received a job offer that qualifies before submission of CPT authorization request

•Job offer must be in students major or field of study

The International Student Office must authorize student CPT. Once student receives CPT authorization, they can only work for the specific employer and for the specific dates authorized (unlike with OPT or severe economic hardship off-campus employment, where they can work anywhere in the US). The CPT authorization will also specify whether they are approved for part-time (20 hours per week or less) or full-time (more than 20 hours per week) CPT employment. While in school, they can only be approved for part-time CPT.

Regardless of whether students are approved for full or part-time on CPT, there is no limit to how long they can work. However, if the student works full-time on CPT for 12 months or more, they are not eligible for OPT. If they work part-time on CPT, or full-time on CPT for less than 12 months, they are still eligible for allowable OPT. Its imperative to watch the dates and hours closely – to avoid jeopardizing OPT!

As with all employment, international student office is the department which is responsible for all the control & reporting. The general rules will apply somewhat differently to undergraduates, graduate students and PhD candidates, the office can help student determine eligibility for CPT, make sure the job offer qualifies, and make sure that student follow all necessary steps in applying to USCIS. They also have to authorize CPT, so students have no choice – have to work with them.
Employment with an International Organization
The final category of employment for international students in the U.S. on F-1 visas is employment with a “recognized international organization.” To qualify, an organization must be on the official State Department list, and listed organizations include the Red Cross, African and Asian Development Banks, the World Health Organization, the World Trade Organization, and many other similar but less well-known organizations. Because it does not have the universal application of OPT or CPT, this category of employment is often overlooked. Only students with a job offer and sponsorship from one of the listed organizations are eligible. However, for those lucky students who do have such sponsorship, there are clear benefits of this employment category.
Requirements to work for an international organization:

•The student must have an internship/employment with a “recognized international organization

•The employment must be within the scope of the organization’s sponsorship, and within the student’s field of study

•The student must have been in valid F-1 status for at least one full academic year

•The student must be in good academic standing

If students meet these requirements, they can apply for an Employment Authorization Document (EAD) from the United States Citizenship and Immigration Service (USCIS). Work can bee started only after receiving EAD, which can take up to 3 months.

There are certain advantages of this type of employment when compared to CPT or OPT.

•Employment does not have to be for-credit nor required for your degree program.

•Regardless of how much or how long student works, this type of employment will not take away from 12-month post-completion OPT