If you are referring to an employee-related expense ( Form W-2), you won't be able to deduct this year, unfortunately.
Due to the new tax reform TCJA, Congress suspended the whole section of the miscellaneous deductions on Schedule A that are subject to 2% of your AGI including the job-related expenses. For tax years after 2017, unreimbursed employee expenses are no longer deductible.
If you are self-employed, see the answer from HelenaC from above.
@feltet5
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