Curricular practical training programs or CPT for Intl students

http://www.uscis.gov/propub/ProPubVAP.jsp?dockey=13272aa308d004ecbbb60f15e0fcf431

Sec. 214.2(f)(10)
(10) Practical training . Practical training may be authorized to an F-1 student who has been lawfully enrolled on a full time basis, in a Service-approved college, university, conservatory, or seminary for one full academic year. This provision also includes students who, during their course of study, were enrolled in a study abroad program, if the student had spent at least one full academic term enrolled in a full course of study in the United States prior to studying abroad. A student may be authorized 12 months of practical tra ining, and becomes eligible for another 12 months of practical training when he or she changes to a higher educational level. Students in English language training programs are ineligible for practical training. An eligible student may request employment authorization for practical training in a position that is directly related to his or her major area of study. There are two types of practical training available: (Introductory text revised effective 1/1/03; 67 FR 76256 )

(from my personal experience, you have to apply in advance so you can work off campus and that sometimes means 2-3 months in advance). CPT is recommend for all international students who can work a summer or two, or even more during regular college year, up to 12 months like it mentions above and after you graduate, your OPT will be good for another 12 months, which can be extended to another 17 months if you're in the fields listed by the INS or USCIS. I believe sometimes employers will likely go ahead and still go through the paper work and troubles if you really are worth it regardless of what field you're in. This means, even though you're not in the fields mentioned in the USCIS, you're good to go! This might be very difficult so be proactive and study in fields so you can get that 12 of CPT for all, + 12 OPT for all, + 17 months of extended OPT for specific fields. That's 41 months of experience before possibly deciding on your futher study programs or investing on immigration fees to carry on your stay as a legal working immigrant.