Your employer most probably mandate this.  The fact is that majority of employment arrangements are what is known as "at will", and PA is no exception.  This means that an employer can hire or fire someone for any reason or no reason whatsoever, as well has increase/decrease salary/hours, promote/demote, and generally impose requirements as they see fit (this includes education exemptions)).  An employee in turn can work for an employer or not, their choice.  There are however certain exceptions that may apply to the above.  For instance, if there is a stated company policy contrary to this, or there is a union/employment agreement that does not allow for such  action, or this situation has arisen due to some type of discrimination (i.e., for reasons due to your race, religion, age, disability, sex, national origin).  Absent anything oof such a nature, your employer's action does not violate the law.