Q. Can I, an instructor, reuse the same file in my e-reserves for my students from semester to semester?

While you should weigh the four factors each time (sometimes talked about as the "four factor test" of Fair Use) and thus before each new "use" of the copyrighted material, there may be no reason why it wouldn't meet the requirements again if it did the first time. But it all depends on if circumstances have changed from semester to semester.

It is actually a myth/misconception that you automatically have to license content all following semesters. However, if the TCC Library suddenly starts subscribing to the journal or ebook from which your e-reserves content comes from, it is recommend you use links to the material instead. Thus, checking the library's holdings should be part of your practice. 

Misconception #2: Fair use can be considered for the first semester of use only. Any subsequent use of a copyrighted work for reserve requires that you pay a license fee for the use.

There are no term limits found in the fair use statute. When a faculty member who has placed a work on print or electronic reserve under the auspices of fair use asks me about reusing the work in subsequent semesters, I encourage them to work through the four factors of fair use again to determine if any of the circumstances of their use has changed. If they have, and if their use of the work may no longer fall within the scope of fair use, we consider other options that may be available to them for making the work [accessible] to students. This could include the utilization of other exceptions found in the law, such as the Technology, Education and Copyright Harmonization Act (TEACH Act) found in Section 110(2) of US copyright law, linking to a copy of the work made freely and legally available online, seeking permission to reuse the work, or obtaining a license to reuse the work.

From Carla Myers, "Fair Use and Course Reserves: Fact and Fiction" in Copyright at Harvard Library