Like most tax questions, the answer to whether mutual fund fees are tax deductible is "it depends." Mutual fund-related expenses you can deduct as "miscellaneous expenses" include fees for investment advice, subscribing to an investment magazine and charges for a firm's automatic investment services or dividend reinvestment plans, according to Charles Schwab. However, even these costs are only deductible to the extent that they exceed 2 percent of your adjusted gross income, and only if you itemize your deductions.
You can't include the cost of commissions when buying and selling your mutual fund shares. The reason you can't deduct these costs is because they are already taken into account when figuring your gain and loss. For example, say you buy $1,000 worth of a mutual fund and pay a $20 commission. The IRS treats it as if you paid $1,020 to buy it. So if you turn around and sell it for $1,050 and pay another $20 commission, which results in $1,030 of net proceeds, you only pay taxes on $10 of gain from the trades.