OPT is temporary employment authorization for F-1 students in degree programs to gain experience in jobs directly related to your major area of study. You are eligible for a total of 12 months of OPT available per education level (e.g. Bachelor’s, Master’s, Doctorate).
OPT Quick Facts:
- You do not need a job offer to apply for OPT
- You may not pursue a new course of study while on OPT.
- The application is approved by United States Customs & Immigration Service (USCIS), but OPT must first be recommended by OIA.
- The approval process for USCIS takes between three and four months.
Pre-Completion OPT (Before program end date listed on I-20)
- Part time while classes are in session (20 hours or fewer per week, cannot be averaged)
- Full time or part time during breaks or vacation quarters
- Master’s/Doctoral Students ONLY: Full-time or part-time after courses finished, while working on thesis
Post-Completion OPT (After graduation, or after completion of course requirements for MA/PhD students)
- Granted on a full time basis only (over 20 hours a week)
- All previous periods of OPT at the same level are deducted from the 12-month total. Part-time OPT is counted at a half-rate. Example: Four months part time OPT is subtracted from the total as two months.
- Eligibiility for Pre- and Post-Completion OPT is based on program end date listed on your I-20, which might be different from your actual graduation date/quarter.
- Registered full-time for at least one academic year (three quarters) in valid F-1 status
- Present in the U.S. in valid F-1 status at the time of application.
If you are outside of the U.S. after your program end date and have not applied for OPT, you will lost OPT eligibility.
Twelve months or more of full time CPT makes you ineligible for OPT.
On-campus employment does not count against the 12-month OPT eligibility.
Employment Requirements & Types of Employment
Employment Requirements (Post-Completion OPT)
- Unemployment: During your initial post-completion OPT period, you can have up to 90 days of unemployment. The STEM OPT extension allows 120 days of unemployment (for the entire time spent on OPT).
- Reporting: You must report all employers to OIA within 10 days of a new job.
- The Student Exchange and Visitor Program (SEVP) recommends that students maintain evidence - for each job - of the position held, proof of the duration of that position, the job title, contact information for the student's supervisor or manager, and a description of the work.
- If it is not clear from the job description that the work is related to the student's degree, SEVP highly recommends that the student obtain a signed letter from the student's supervisor or manager or the employer's hiring official stating how the student's degree is related to the work performed.
Types of Paid Employment:
- Multiple employers: You may work for more than one employer, but all jobs must be related to your field.
- Short-term multiple employers (performing artists): You’re allowed to have multiple short term jobs or gigs (e.g. music performances). Keep a list of all gigs, the employer, and duration of each.
- Work for hire: Commonly referred to as 1099 or Independent Contractor Employment; keep evidence of the duration of contract periods and the name and address of the contracting company.
- Self-employed business owner: You can start a business or be self-employed while on OPT. You should be able to prove that you have the proper business licenses and that it is related to your degree program.
- Employment through an agency or consulting firm is also allowed.
- You may work as a volunteer or unpaid intern, where this practice does not violate labor laws.
- You can apply for OPT from 90 days before your end date, until 60 days after your end date.
- Your OPT start date can be between the day after your end date and 60 days after your end date.
- If you are outside of the U.S. or leave the U.S. after your prorgam end date and you have not applied for OPT, you will lose your OPT eligibility.
Learn more about the timeline and start date for your post-completion OPT application:
STEP 1: OIA Recommendation
Submit the following three documents to OIA (You do not need to see an adviser unless you have specific questions):
- You must include OPT start and end dates on this form.
- When choosing an OPT start date, make sure you consider your proposed job start date, class schedule (for pre-completion OPT), your plans for future study at the same degree level, and potential H-1B plans.
2. Verification of Completion Form
(For Post-Completion OPT Applications Only)
- Confirmation signed by your faculty adviser/Dean of Students or College Academic Adviser verifying that you will complete either all course requirements with the exception of the thesis OR all degree requirements by the expected graduation date.
- This is the official application form sent to USCIS for OPT work authorization. Fill it out online and then print it (writeable pdf format). DO NOT file electronically!
- Instructions for the Form I-765:
- Mark the first box, “I am applying for: permission to accept employment”
- Item 1: Print your entire name as it appears in your passport and on Form I-20. Last name in capital letters, first name lowercase. Ex: BONAPARTE Napoleon
Item 3: This is where your EAD will be sent. You must select an address that will be valid for the next 4-5 months. If your address will change, use the address of a friend or relative. EADs will not be sent abroad.
- NOTE: OIA does not permit the use of our address for completion of this form.
- When using a friend or relative’s address, write “c/o” followed by the individual's first and last name in the address field. The c/o stands for, ‘in care of.’ Ex: “c/o Wolfgang Mozart”
- If the address you write is outside of Illinois, you may be required to mail your application to another USCIS Service Center. Check the USCIS website for the correct mailing address.
- The U.S. Postal Service will NOT forward government mail to a new address.
- If you live in an apartment, put “APT” in front of your apartment number
- Include the last four digits of the zip code (Ex. 60637-2916) Check the U.S. postal service website for the complete zip code: http://zip4.usps.com/zip4/welcome.jsp
- If you entered the U.S. on or before April 29, 2013: This can be found on your I-94 Departure Record card.
- If you entered the US on or after April 30, 2013: Visit the USCBP website to retrieve your I-94 number.
- Item 11: If you have submitted an application for OPT work authorization from USCIS (had an EAD card) in the past, check “yes.” CPT & on campus employment do not count
- Item 12: Enter the date of your last entry into the U.S. (see admission stamp in your passport).
- Item 13: Enter the port of entry you last came through (on the entry stamp in your passport).
- Item 15: Enter “F-1 student.” If you have changed status since your last entry, include a copy of your Form I-797 Approval Notice as proof that you are now in F-1 status.
Item #16: Enter code:
- Pre-completion OPT: Enter code: (c)(3)(A) and hand write “F-1 Pre-completion Optional Practical Training” next to or above it.
- Post-completion OPT: Enter code: (c)(3)(B) and hand write “F-1 Post-completion Optional Practical Training” next to or above it
- SIGN and date!!! Your signature must stay in between the parallel signature lines, as the image of your signautre will be caputred for your EAD.
OIA will review your documents and create a new I-20 that shows your OPT request. Sign your I-20 at the bottom of page 1. You will also receive your original Form I-765 and screen shots from SEVIS showing any previous OPT or CPT time used at U Chicago. Allow at least one week for OIA processing. You will receive an email confirmation when your new I-20 is ready. Then you can move on to Step 2.
Mail the following documents to USCIS:
- Form I-765 with fee and photographs in an envelope stapled to it (see items #2 and #3 below).
- Two new passport style photos in color. Available at the ID & Privileges Office in Regenstein, Walgreens, and CVS. Write your name with a pencil on the back of the photos and put them in a small plastic bag or envelope and staple it to the top of Form I-765. Your photos must be recent and must not have been used in any previous application,
- Payment: A check for the filing fee of $380 payable to "Department of Homeland Security." You can use a personal check or a money order. Staple your completed and signed check to the front of the I-765. Make sure the check has your current address. If it is incorrect, you can cross it out and handwrite your new address.
- Copy of I-20 (the one with the OPT recommendation on it), all pages. Sign the I-20 at the bottom of page 1. DO NOT SEND ORIGINAL. The OIA signature must be less than 30 days old at the time the application is received by USCIS. You do not need to send copies of any additional UChicago I-20s; just include the copy with your OPT recommendation.
Documentation of your I-94:
- If you entered the U.S. on or before April 29, 2013: Photocopy of your I-94 Departure Record card, front and back.
- If you entered the US on or after April 30, 2013: Visit USCBP website to retrieve and print out a copy of your electronic Form I-94
- Screen shots from SEVIS of OPT and CPT use (you will get this from OIA with your new I-20).
- Copies (front and back) of all previous EAD(s) issued to you for OPT.
Copies (front and back) of all I-20s from any previous U.S. institution before the University of Chicago.
- This includes high school (if you attended high school in the U.S. in F-1 status).
- If you are missing copies of some or all of your previous I-20s, you can first try contacting your previous school to see if they have a copy. If this does not work, you can create a letter of explanation that details your previous program(s) and any CPT or OPT you were authorized for.
- Copy of the identity page(s) of your passport. This includes the page that has your photograph and biographical information. You do not need to include a copy of your F-1 visa.
Form G-1145, "E-Notification of Application/Acceptance," if you want to be notified electronically when your application is received. See http://www.uscis.gov/files/form/g-1145.pdf for form and filing instructions.
STEP 3: Mail Your Application to USCIS:
- Make a copy or scan and save your entire application before mailing it; keep the copy with your mailing receipt.
- We recommend secure mail with delivery confirmation/tracking, such as U.S. Postal Service Certified Mail. FedEx, UPS, DHL, etc will not sent to P.O. (Post Office) boxes, so you will need to mail your application from a post office.
- Check with your OIA adviser if the address on Item 3 of your I-765 is outside of Illinois. If you are not using an Illinois address, you can find the correct Lockbox address on the USCIS website.
- Applications with an Illinois address go to the USCIS Lockbox facility in Phoenix, Arizona:
PO Box 21281
Phoenix, AZ 85036
Use the U.S. Postal Service's certified mail, return receipt requested.
Before you mail your application, make scans or photocopies of your entire application plus supporting documents, and keep them with your mailing receipt.
Checking Your Application Status
Ways to tell if your application was received:
- If you filed Form G-1145, you will receive an email or text from USCIS with confirmation that your application was received and a receipt number.
- If you paid the $380 fee with a personal check, check your bank account to see if the check has been cashed.
- Within a month of mailing your application you will receive a Receipt Notice (I-797) from USCIS. The Receipt Notice contains an receipt number (upper left-hand side) that you can use to check the status of your application on the USCIS Case Status Search Page: https://egov.uscis.gov/cris/Dashboard.do
Contact OIA if you:
Need to cancel your OPT application
Don’t graduate as planned
Need to update your mailing address on your I-765
Contact OIA immediately. DO NOT TRY TO UPDATE THE ADDRESS YOURSELF!
Employment Authorization Document (EAD)
- USCIS will issue an EAD when your application has been approved. The card will state the specific start date and end date for your OPT.
- You cannot legally begin working until you have the physical card and the start date has been reached!
- All F-1 students on post-completion OPT are required to report any change in the following information within 10 days through the OPT Update Form: Name, address, employer name/address, dates on EAD card, and/or any interruption of employment.
- If you change your status, provide evidence (e.g. approval notice, I-94 card) of the new status to OIA so that we can complete your SEVIS record appropriately.
- If you leave the country before your period of OPT authorization has completed, please provide documentation of your departure so OIA can update your SEVIS record appropriately.
- If you plan to start a new program either during or after completion of OPT, you can have your SEVIS record transferred. This can be done up to the end of the 60 day grace period following your OPT end date.
- Please note that if you transfer your SEVIS record while on OPT, you will lose work authorization the day that your record is transferred, regardless of the end date indicated on your EAD Card.
While OPT is PENDING
- Before Program End Date: You can travel normally as an F-1 student. NOTE: Contact employer for travel information if you are applying for H-1B or another immigration status.
After Program End Date: It is not advisable to travel outside the U.S. prior to receiving your EAD card and securing employment.
- EAD cards will NOT be sent overseas, and an EAD card is required for re-entry. After your program end date, you will need proof of employment to show you are returning to the U.S. to resume employment appropriate for OPT, in addition to the EAD and other travel documents.
- Travel through Chicago airports whenever possible!
- You can remain in the U.S. if your F-1 visa has expired. If you plan to travel in and out of the US while on OPT, you must have a valid F-1 visa.
- If your F-1 visa will expire before you re-enter, you must apply for a new visa at a U.S. Consulate or Embassy abroad PRIOR to your return.
Once OPT is APPROVED
- If you have completed your studies AND received your EAD card: You may depart and re-enter the U.S. in F-1 status.
In addition to your regular travel documents (valid passport, valid F-1 visa, I-20 with OPT recommendation and travel signature less than 6 months old), you will also need:
- Valid EAD Card
- Job offer letter or letter of employment verification from your current employer. There is no template for this or specific information the letter must include.
NOTE: Without your EAD AND proof of employment/job offer you assume risk in re-entering the U.S. while on OPT.
F-2 Dependent Travel
In addition to their own Form I-20 – with updated travel signature, passport and valid F-2 visa, F-2 dependents should keep copies of the following F-1 documents for travel:
- F-1 Form I-20
- F-1 Visa
- F-1 Passport identification page(s)
- F-1 I-94 Departure record, if available
- EAD with proof of employment/job offer
This is a post-completion OPT extension for which students holding Science, Technology, Engineering, and Math degrees are eligible to apply. See this page for more information on the STEM Extension.
The "H-1B cap-gap" refers to the period of time between the end of a student's F-1 status (end of OPT or grace period) and the beginning of the student's H-1B status. If a student has an H-1B application pending with or approved by USCIS, the cap gap extension rule automatically extends an eligible F-1 student's authorized period of stay in the U.S. during this "gap" period until the H-1B status becomes active (October 1).
This extension will extend your:
Duration of status:
If your OPT expired prior to April 1, [current year], or if you are in your 60-day grace period, this extension will allow you to remain in the U.S. provided you maintain your status. You are not permitted to work under any circumstances until your H-1B petition has been approved by USCIS and your H-1B status is in effect (October 1).
Current period of OPT:
If your approved OPT work authorization ends April 1, [current year] or later, your work authorization will be extended from the date it expired until September 30th, the day before your H-1B status becomes active.
This extension is available to F-1 students whose OPT was approved or who were in their 60-day grace period as of April 1, [current year] and have a pending or approved H-1B petition with USICS. The H-1B petition must have been filed in a timely manner with USCIS, according to the acceptance period, and must be filed requesting a change of status (as compared to requesting consular processing).
Cap Gap Application process
It is important that you work closely with your OIA adviser during this process. You will need to contact OIA to request the Cap Gap Extension I-20. Your adviser will then print the new I-20 showing USCIS automatically extended your F-1 status. Please allow a week for your request to be processed. It is essential that you notify your adviser when your H-1B petition has been approved or denied by USICS, so they can update your record as necessary.
If your OPT will run out before you get the receipt from USCIS, such as if your OPT expires in early April, you can submit a copy of your FedEx tracking confirmation and a letter from your immigration attorney as proof that the application has been filed, and your adviser can extend your OPT through June 1, [current year].
Denial of H-1B Petition by USCIS
If a pending H-1B petition is denied, rejected or revoked, the extension of status or work authorization will be terminated immediately. The standard 60-day grace period will apply from the date the H-1B petition was denied, rejected or revoked. You must stop working immediately upon receiving notice that your petition was denied, rejected or revoked. You will then have 60 days to leave the U.S.
Traveling while on Cap-Gap Extension
You will not be able to travel during the cap gap extension period. Requirements for travel while on OPT include having an unexpired EAD. You will not receive a new EAD for your cap gap extension. Because your EAD will have expired, you will not be able to re-enter the U.S. if you travel abroad. If you must travel abroad, please speak with your OIA adviser for more detailed advice.
When can I apply for OPT?
Post-Completion OPT: You can apply up to 90 days before and up to 60 days after the program end date listed on your I-20. See the OPT application section for more information. You will not be eligible for post-completion OPT if you leave the U.S. after your program end date and have not applied for OPT.
Pre-Completion OPT: You can apply up to 90 days before your requested employment start date.
Can I split up my OPT into multiple segments?
You are eligible for only one post-completion OPT segment per completed program of study. You must begin post-completion OPT within 60 days of your program end date. Any OPT you do not request or use will be forfeited. At the same level, you can split post-completion OPT into multiple sections ; for example, you can use six months of OPT after completing a master’s program in computer science, and use the remaining six months after completing an MBA. However, if you choose not to apply for OPT at the time you complete a program, you cannot go back at some point in the future and claim that OPT time. In this sense, OPT is a ‘use it or lose it’ proposition.
You can apply for multiple segments of pre-completion OPT; for example, you can use pre-completion OPT during two separate summers while you are a student for an internship or job.
The only way to extend your post-completion OPT is by using the STEM or H-1 Cap Gap Extension (if eligible).
Do I need a job offer to apply for OPT?
No. OPT is not employer specific. You do not need a job to apply for OPT. You will not include any information about your employer in your post-completion OPT application.
I used 3 months of CPT. Will that time be deducted from my 12 months of OPT?
No. If you use one year (12 months) of full time CPT, you will be ineligible for OPT. Other than that, CPT has no effect on OPT eligibility. If you used only three months of CPT, you will still have 12 months of OPT available.
What does my employer need to provide for the OPT application?
Nothing. OPT is not employer specific. Your employer does not need to provide any documentation for your OPT application.
How can I tell my OPT application has been received?
When USCIS receives your application, they will send you an I-797 receipt notice through the mail. This receipt notice will have your receipt number on it. If you filled out a G-1145 request for electronic notification, you will be notified through email or text messages that it has been received. If you paid the application fee by check, you can see if the money has been removed from your account.
Is there expedited OPT processing?
No. There is no expedited OPT processing. OPT takes about three months (90 days) to get approved. If you have a upcoming job start date or issue with your OPT application, please contact your International Student Adviser as soon as possible.
My OPT application is pending and I have moved to a new place. What should I do?
If your address has changed since you applied for OPT, contact your International Student Adviser as soon as possible. Do not attempt to contact USCIS and update the information yourself. Address issues are one of the biggest complications we see with OPT applications, so it is important to contact your ISA early if there are any changes in your application.
I have lost my EAD card, how can I get a replacement card?
If you lose or misplace your EAD, you will need to start from scratch and reapply for a new EAD. The only difference between applying for a new card and applying for a replacement is checking one box on the I-765. For the replacement card, you will have to submit an entirely new application with all supporting documentation, pay the $380 fee again, and wait for your application to be processed.
Can I stay in the U.S. while my application is pending?
Yes. As long as the service center receives your application before the last day of your Grace Period, you can stay in the U.S. until your OPT is approved.
Can I travel out of the country while on OPT/after it has been approved?
Yes. OPT is a continuation of your F-1 Student status. As an F-1 Student, you are allowed to enter and exit the country as long as you have all required travel documents. After the program end date listed on the I-20, you should not travel out of the country until you receive your EAD (see below).
If you have an H-1B or other status petition pending, make sure you speak with the attorney or HR representative preparing your case before travelling out of the country.
Can I travel before I receive my EAD card?
OIA does not recommend that you travel before you receive your EAD card. After the program end date listed on your I-20, you will need your EAD to re-enter the country. If you leave the U.S. before you receive the card, you will not have it for re-entry and risk being refused entry. If you have an urgent situation that requires you to travel before reviving the EAD, contact your International Student Adviser.
Visit the Immigration and Customs Enforcement (ICE) travel FAQ website for more information.
Pre-completion OPT and travel before your program end date will not affect your eligiblity to travel internationally.
Can I travel during spring break while my OPT application is pending?
Yes, as long as it is before the program end date listed on your I-20. If you are travelling before your program end date, you can travel like a regular F-1 student, even if you have an OPT application pending. If you are traveling after your program end date, you will need your EAD and a letter from your employer, in addition to your regular travel documents, to re-enter the U.S. We do not recommend travelling out of the country after your program end date until your OPT has been approved and you have your EAD in hand. See our page on Required Documents for Travel for detailed information.
If you have an H-1B petition pending, contact the attorney or HR representative before traveling out of the country.
I'm studying/doing research abroad during my final quarter of study. How does this work with the OPT application?
This is not recommended, but technically possible. You must be in the U.S. when you apply for OPT, so you will either need to apply for OPT before you leave (see the application timeline above) or come back before your I-20 end date and apply for OPT after your trip. If you do not apply for OPT and your I-20 end date passes, you will not be allowed to re-enter the U.S. in F-1 status and you will lose OPT eligibility.
Also note that all communication about your application will be sent to your U.S. address and will not be sent abroad. If there are issues with your application or you receive a Request for Evidence (RFE), you must be able to respond to it to keep your application active.
Can I renew my F-1 visa while on OPT?
Yes. OPT is a continuation of your F-1 Student status. As an F-1 Student, you are eligible to apply for a new F-1 visa while on OPT. For details, visit our Visa Renewal Information page.
My EAD says ‘Not Valid for Travel’ on it. Does that mean I can’t travel?
Your EAD should say ‘Not Valid for RE-entry.” The statement means that the EAD document alone is not sufficient for re-entry. The EAD work authorization card does not replace your visa and other immigration and travel documents. You need the EAD in addition to your regular travel documents (I-20 with travel signature- signatures are only valid for 6 months while on OPT, passport valid at least 6 months into the future, valid visa, etc). You can see all of the documents you need for travel on our website.
What counts as employment while on OPT?
‘Employment’ is any job or work opportunity that is directly related to your field of study and combines for an average of 20 hours per week. It can be paid or unpaid, research, multiple short-term gigs, contract work, full time office jobs, really anything—as long as it is related to your field of study, does not violate labor laws, and is an average of 20 hours a week, it counts as ‘employment’.
Can I do an internship while on OPT?
Yes, as long as the internship is relevant to your field of study. There is no minimum amount you must be paid or limitation on the type of work that can be done for your job to ‘count’ for OPT. The job can be paid, unpaid, full time, part time, contract work, etc. As long as the job is directly related to your major/field of study and does not violate any labor laws, it can count towards your 20 hour/week requirement for OPT.
What does “directly related to your field of study” mean? Who makes that determination?
It is your responsibility to have a job that is relevant to your major or field of study. This means you are using the skills and knowledge you developed in your major/degree program in the job you are doing and your job is appropriate for your level of edudation. Basically, if the government were ever to question you on how your job is related to your studies, you and your supervisor would be able to defend how your program and skills learned while in your program are necessary for the work. For details, see our information on Showing your OPT is directly related to your degree program.
What's the longest I can go without having a job on OPT?
You are allowed 90-days of unemployment while on post-completion OPT. Unemployment time starts 'counting' on the OPT start date listed on your EAD (the card you get when your OPT has been approved).
Is there a grace period after I have reached 90 days of unemployment?
No. If you have exhausted your 90 days of unemployment and are not employed at least 20 hours per week, we recommend you leave the country immediately and inform OIA so we can cancel your remaining OPT time. You are allowed 90 days of unemployment for the duration of your OPT. If you stay in the U.S. without a job after you’ve been unemployed for 90 days, you will begin to accrue days of unlawful presence. This can cause negative immigration consequences, especially for future U.S. immigration applications.
Unpaid internships or volunteer positions count as OPT employment. While you are looking for something more permanent or paid, you may want to consider finding a non-profit or other volunteer opportunity related to your field. Working will stop the unemployment clock and give you more time to search for a job. It doesn’t have to be your dream job or something you want to do forever.
I received my EAD card; what do I have to do now?
Once you receive your EAD, submit the approved dates on your EAD through the OPT Update Form. You will also use this update form to inform OIA of any changes to your employment status, employer, or address. See OPT Reporting Requirements for more information.
Is there a grace period after my OPT ends?
Yes. There is a 60-day Grace Period after the work authorization end date listed on your EAD. During this time, you will either need to leave the country, change to a new immigration status, or transfer to a new program. You are not allowed to work during this time. Please see our information on the Grace Period for details.
Can I continue to work during my grace period?
No. The last day you can be legally employed is the work authorization end date listed on your EAD. After the end date, you can no longer work on OPT. You will have 60 days to leave the country, change to a new immigration status, or transfer to a new program.
What do I do if want the leave the U.S. and I don’t want to continue my OPT?
If you want to quit working and leave the country before your OPT has ended, that is fine. Just makes sure you notify OIA so we can cancel your remaining OPT time. If you do not notify OIA, we won’t know to complete your record and you may end up accruing a lot of unemployment time (more than your 90 day limit). This would have a negative impact on your immigration status and could cause complications for future U.S. immigration applications—especially for work statuses.
I studied in a STEM field. How can I know if my company is in the E-Verify system, and if it is, how can I find the company’s E-Verify number to complete the I-765?
To apply for the STEM extension, you must have a job offer from and E-Verify employer. USCIS keeps a database of E-Verify employers on its website; you can check for your employer on this list. To find the E-Verify number, speak with the company’s HR department or your recruiter.
Should I move to H-1B as soon as possible, or are there benefits to staying on OPT?
There are a few benefits to utilizing your OPT time before starting on H-1B. First, OPT provides flexibility for both you and your employer. OPT is not employer specific; this means you can have multiple employers and change jobs. This gives you the opportunity to ‘test out’ your employer; if it turns out that the position is not for you, you can find a new job with little hassle. It also gives you a chance to show your skills and build a relationship with your employer, which could lead to sponsorship in the future.
Logistically, OPT will give you an opportunity to work in the U.S. if a different work status application is not selected for processing or approved. Having a year of OPT may allow you to participate in multiple H-1B application period. Speak with the company that is going to sponsor your employment status for more information on application timing, eligibility, or other questions.
OPT also adds time to your work eligibility in the U.S. H-1B status is limited to a finite number of years. OPT can give you extra time to work in the U.S.