In Michigan an most employees are considered to be an at-will employee. The term at-will is thrown around and few really understand what it means. Most assume or use the term to mean that an employee is fireable at the whim of the employer. While there is truth to this idea, it hides the complete meaning and the history of the rule.
The seminal case in Michigan is _Toussaint v Blue Cross_, 408 Mich 579 (1980). This case analyzed the relationship between the employer and the employee. The case is still - 30 years later - the most commonly cited case for at-will employment.
The most striking part of the _Toussaint_ was that the case was really about whether the employer had hired the employee and promised to only discharge for cause. For cause being the opposite of at-will and meaning that an employee can only be terminated where the employer has sufficient reasons to terminate. Most collective bargaining agreements include language that an employee can only be discharged for cause. The Court further found that an employment contract for a period of time is implied to be for good cause.
The court looked to the employment policies of the employer. It found that a jury could conclude from the personnel policies that the employer had created a contract and promised to only discharge for cause. This is the reason that most - if not all now - employment handbooks and applications contain a statement that the employment relationship is at-will. For lawyers, this is the way of maintaining that regardless of what the handbook says the relationship is terminable at-will.
The Court found that where for-cause relationships exist, the jury and not the employer are the final arbiters of whether or not cause existed.
What does it mean for the employee. If the employer has made any promises of a term of employment or that the employment is terminable only for cause, the employer will be held to that standard. This is what is know as a wrongful discharge claim or breach of contract. Today there are not many wrongful discharge cases, because most employment is not for cause.
At-will employees cannot bring wrongful discharge cases. If you are an at-will employee you can be terminated for no reason or any reason. There is a very big exception to this rule. Michigan and the federal government have enacted statutes that provide that employees cannot be fired for certain things. So while an employer can terminate you for most reasons, they may not terminate you because of race, gender, age, disability, religion, because you report violation of law, participate in an investigation of a state agency, or other protected reasons.
If you live and work in Michigan chances are your employer can terminate you legally unless they are doing it illegally because of a protected reason.