The Massachusetts Wage Act allows an employee to recover "wages" that have been "unreasonably retained" by an employer. A salary is within the scope of the statute. What else is considered "wages"? It's not clear because the term "wages" is not defined. The statute simply provides that the term "wages" includes holiday and vacation time but such enumeration is not exhaustive. Courts have interpreted the term "wages" to mean wages that have been "earned," as opposed to wages that are contingent on some other fact or are discretionary. For example, accumulated sick days are not "wages" because they are contingent on a specific fact, i.e. the employee being sick. The same is true for bonuses since they are paid at the discretion of the employer. Commissions, however, are generally considered "wages" if they are not discretionary and are the result of the employee's work, provided that the amount of the commission is definitely determined and due and payable.