Courses stay on Blackboard for a year after the course ends,  so as long as the instructor leaves the course available,  the student will have access.

 

If the instructor does not want other students to access the site after the course ends he/she can change the availability of the other students.

  • Control Panel
  • Users and Groups
  • Users
  • Change User's Availability in the Course 
  • For every student who does not need access,  s/he can change the availability for Yes to No.