If you graduate, you will get the Alumni role added to your profile and then you will have access to your account as long as you use it.

Unused alumni accounts will be purged after 1 year without a login.

If you leave without graduating, your account will remain accessible until the following year’s tax season is over (allowing you time to access the previous year’s 1099-T info).

Inactive alumni accounts are no longer kept in the system as of April 15th, 2007.

Normal mail expiration policies are still in place! Plan accordingly.  See Also: How long does mail stay in my @mail.usi.edu (myUSI) mail account?