I'll take a crack at it, although you will find much disagreement...mainly related to the idea of pro-rating the deduction for the first and last day. Do a search and you can find the threads about that argument. I won't go into detail here but I feel that the IRS is very clear that you can take the entire day's value. So anyway, 40 4-day trips would be $52 X 4= $208 X 40 = $8320 allowable deduction. That figure would go on your Form 2106 under column B, meals and entertainment. Then, also on Form 2106, you would subtract your ntax perdiem of $4000 leaving a deduction of $4320. Then you take 80% of that (for 2008 taxes). That amount from form 2106 gets placed on your schedule A, itemized deductions, on line 20. The amount(plus any other miscellaneous deductions) that exceeds 2% of your AGI is deductible on your schedule A.