Generally speaking any non essential functions will be shut down. IRS will close, but if you filed electronically and are getting your refund electronically that should still go through. Military will still earn a paycheck, but you might not actually get paid (much like anyone furloughed). I'd guess most social security, va, etc would still go thorugh as they are automated payments. Haven't heard about DFAS but if the payment is scheduled, it'll probably go through. If not, there may be a delay.