If you're referring to the rufund due to paying taxes on your severance pay, this is what I found on the DFAS website:
If you paid taxes on your disability severance pay, you could be due a refund. A refund is awarded in the same calendar year in which a military member received disability severance pay. To obtain a refund from us you must submit the following documents to us before December 15th if the year in which the disability severance pay was paid.
DD For 214 (member copy 4
Veterans Affairs Award letter (the Award Letter in its entirety
Separation Order
Physical Evaluation Board (PEB) Proceedings Form from your applicable service.
Army - DA 19
Air Force - AF 10
Navy (does not have an identifiying form number)
We cannot issue refunds for prior tax years. If you received your funds in prior tax years please contact the Internal Revenue Service at 800-829-1040.
But you are only exempt from paying taxes on your severance pay if you meet the following criteria:
1. You have a combat related injury or illness as determined by your military service at separation that:
Resulted directly from armed conflict;
Took place while you’re engaged in extra-hazardous service;
Took place under conditions simulating war, including training exercises such as maneuvers; or
Was caused by an instrumentality of war.
2. You are receiving VA disability compensation or you have received notification from the VA approving such compensation