What issues can collective bargaining address?

According to the National Labor Relations Board (see page 20), there are three categories of issues with regards to collective bargaining. Mandatory issues, such as wages, hours, and terms and conditions of employment must be bargained over. Illegal issues would be those that would contravene state, local, or federal laws. Non-mandatory issues are everything that is neither mandatory or illegal, and could include issues such as housing, professional development programs, programs for international students, etc. For example, the University of Michigan graduate union used the collective bargaining process to ensure paid graduate student positions on the university’s diversity, equality and inclusion committee.