The only time your can deduct commuting expenses is if your are involuntarily displaced to another base. Then it is considered a "temporary assignment" for up to a year and is deductible. Example: I was involuntarily displaced from CAK to DAY until I voluntarily bid for a transfer to TYS. For those two months in 2005 that I was based in DAY, I was eligible to deduct all out-of-pocket hotels, etc. Otherwise you cannot deduct commuting expenses. Living out of base is a personal choice.