You should know that if you have dependents enrolled in DEERS and are TDY for more than 30 days continuously, then most likely qualify for an extra $250 each month you're away. Your family must not be located in the same area as your TDY location to be eligible for the Family Separation Allowance. If you return after 31 days and are back at your Permanent Duty Location for 29 days or less and then depart on TDY again for another 31 days or more, you will qualify for Family Separation Allowance for the time you are away as well as the short time you were back at your Permanent Duty Location in between TDY assignments.
If you leave on Temporary Duty to a location more than 50 miles from your family for 31 days, then return to your duty station for 20 days, followed by another Temporary Duty assignment for 31 days. You will be paid for 31 days plus 20 days, plus 31 days for a total of 82 days.
Family Separation Allowance is $250 each month, and a month is calculated as 30 days. So that you should receive $250 for the first 30 days, $250 for the second 30 days, and the last 22 days are pro-rated at $250/30 times 22 = $183.
Your total pay would be $683.
Keep this in mind whenever you go TDY for anything over 31 days. This is not automatic, and you must fill out the proper form requesting Family Separation. If your leadership does not mention this to you, then be sure to bring it up to them.
For more information, see DoDFMR Vol. 7A chapter 27 or visit www.DFAS.mil.