Curricular Practical Training (CPT) is employment that directly relates to your major and the experience must be part of your program of study.
The ISO authorizes CPT in conjunction with your student advisor. You will receive a new Form I-20, “Certificate of Eligibility for Nonimmigrant Student Status,” that shows that the DSO has approved you for this employment.
You can work on CPT either full-time or part-time. You must have one full academic year of study in the U.S. before you are eligible for CPT.
CPT requires a signed letter from your employer. The letter must consist of the following information on the employer’s letterhead: the EXACT PHYSICAL ADDRESS (Street, Suite # if any, City, State, and Postal Code) of the internship, the duration of the internship including the start and end dates, and a general description of duties.
If you have 12 months or more of full-time CPT, you are ineligible for OPT, but part-time CPT is fine and will not stop you from doing OPT.
After you have been approved to do CPT by the ISO then you may get your social security card.