For some taxpayers in military service and on duty outside the United States, the time for taking care of certain tax matters can be postponed. The deadline for filing tax returns, paying taxes, and taking other actions with the IRS is automatically extended if either of the following is true:
If you qualify, your deadline for taking actions with the IRS is extended for 180 days after the later of:
In addition to the 180 days, your deadline is extended by the number of days that were left for you to take the action with the IRS when you entered a combat zone (or began performing qualifying service outside the combat zone) or began serving in a contingency operation.
Please refer to IRS Publication 3 Armed Forces' Tax Guide for the complete guidelines regarding the filing extension deadline.