I pay my broker a fee for managing my
investments, making trades for me, and giving advice. Am I correct that all of
this fee is allowed as an itemized deduction on my tax return?
Yes and no. If part of your fee is for managing assets which produce tax-free income, you are expected to prorate the fee so that your deduction is only for the part of the fee that relates to taxable income. Also, if you pay a custodial fee for an IRA account, that fee is not deductible.