If you passed a civil service exam and are on a current certified list when you are called to active duty, you can keep your place. You have to ask in writing within one year of your discharge to be continued on or restored to the list, and the protection runs for a period equal to your time in military service. If you are on more than one list, you have to ask for each one separately.
Write to the Massachusetts Human Resources Division civil service unit within one year of your discharge, asking to be continued on or restored to each list you are on.
Your activation orders, your discharge paperwork, and the name of each civil service list you are on.