401k fees are never and never were deductible. The whole point of a 401k is that you put tax-free income in, and pay tax on whatever you take out. If you take out less because of fees, you pay less tax.
Other investment advisory fees are a 2% miscellaneous deduction. That type of deduction is disallowed for 2018-2025 as part of the tax reform that raised the standard deduction instead, among other things.
