Per UCSB OISS's website: 

April 15 is "Tax Day" in the U.S. 

If you earned an income from any source between January 1 and December 31 of any given year, you must file both Federal and State income tax returns.

If you did not earn an income, you are still required to file Form 8843. This short form is not an income tax return but an informational statement required by the U.S. government. More information can be found on page 3-4 of the form.

Unfortunately, OISS nor PaCE is not able to assist with tax advice or filing in any way.

Scholars and students are fully responsible for filing their own taxes. You can find resources to help with this at the link to OISS's website above.