Ok, I admit -- this isn't my area. I'm mostly a labor lawyer. lol.

So, alright, the rule for me right now, assuming I'm taxed on my full salary, is I will pay $5081.25 plus 25% of any amount in excess of $36,900. So, I pay $5081.25 + .25(48496) = $17,205.25.

Assuming my entire income is taxable after the promotion, I pay $18,193.75 plus 28% of any amount in excess of $89,350. So I pay $18,193.75 + .28(8307) = $20,519.71.

If I max out my TSP under a traditional investment account, my taxable income after the promotion will be $80,157 and my tax liability will be $5081.25 + .25(43257) = $15,895.50. Of course, I have to pay taxes on that $17,500 at some point.

ETA: I already had my student loan interest deduction phased out. I used to be able to get it, but now that's completely phased out and will continue to be so regardless of what I do. I'm not sure what other credits/deductions will be phased out. My taxes are fairly simple -- I'm single, no kids. I take a mortgage interest deduction, which would not change (except for the lower amount of interest paid each year as I pay off the principal).