Military pay you earn on active duty in a combat zone or Qualified Hazardous Duty Area that is excluded from your federal adjusted gross income is also exempt from California income tax. You also get extra time to file and pay: 180 days after you return from a combat zone or Qualified Hazardous Duty Area, plus the number of days you served there, with no interest or penalties. If you served outside the United States but not in a combat zone, you get 180 days from your return. Both extensions cover you and your spouse whether you file singly or jointly.
There is nothing to apply for. Leave your combat zone pay out of the income you report on your California return, and file within the extended window.
Your Leave and Earnings Statements or orders showing your combat zone or overseas service dates.
